This page contains the most complete and detailed help topics on troubleshooting the GL1800 Audio System that you will find anywhere. This page should help reduce No Problem Found returns. I hope everyone finds this to be a valuable resource.
I suggest that you save the link to this page instead of printing it out or saving it to your computer. I will peridocially update it and add new information. By saving it as a link, you will always have the most up to date information. (Hit the refresh button when returning to this page to make sure you are viewing the current revision.)
Except where noted, these troubleshooting steps are valid for all 2001 to 2010 Goldwings.
Readers should keep in mind that in many cases, add on accessories such as Mike Mutes, external aftermarket amplifiers, or other devices can create additional troubleshooting steps, can skew your test results, and in many cases can also be the cause of your problem. It would be impossible to account for all the various customizations that are out there, although I do mention a few of them in the articles. There is a saying in electronics that is used when test results don't make sense or get confusing. It's called "Go back to Vanilla". Often times, removing add on devices whenever possible makes things easier, and can even expose the problem.
Click on any of the topics and you will be taken directly to that article. Click on "Return to Index" at the end of every topic to return to the top of the page.
The Honda CB's performance gets unfairly maligned on the forums, except for the fact that it is grossly overpriced. There have actually been very few problems with the CB. Most problems are actually problems in the bike's wiring, not an electrical problem in the CB itself. These problems are many times frustrating because they are usually intermittent. Hopefully I can unravel some of the mystery here and help you to get the most out of your CB. These troubleshooting tips apply to the Honda OEM CB only. I do not service or provide support for the discontinued BikeMp3 units.
No need for an article on this one. Your answer is right here. This problem is not very common, but does show up from time to time. It is usually caused by bad grounds, either at the radio or the 14 pin CB connector under the top shelter. Check the CB power ground and battery ground while you are at it.
This one is at the top of the list because it is the most common audio problem encountered by Goldwing owners. This problem is easy to troubleshoot. The bike can be the cause of the failure just as easily as the radio, so this troubleshooting step needs to be done before sending your radio in for repair.
The only thing you need for troubleshooting is a known good headset and lower cord. Any good tech always makes sure his test equipment is working before troubleshooting, and this is no different. Either borrow a known working headset, or verify yours works on another bike. That includes the lower cord. You can even take your helmet and lower cord to your local dealer to ask if you can check it on a stock bike. Don't assume that it works just because it worked yesterday. Failure to test and verify your headset is just a good way to get your radio back from service with a no problem found diagnosis.
The GL1800 radio has two separate power amplifiers, one for the external speakers, and one for the headsets. This is why you can lose headsets but still have external speakers, and the other way around. The audio from the 2 channel headset amp is split off in the radio at the external connectors and shared by the driver and passenger connectors. This is a key piece of knowledge to have in your troubleshooting arsenal, because it quickly becomes obvious that if either one of the headsets works, then the radio has to be ok. If the headset works at one connector and doesn't work at the other, you have a problem somewhere in the bike's wiring.
If audio is out at both positions, there is probably a problem in the radio. This of course assumes that the headset used for testing is good. It also can't account for the incredibly rare and unlucky situation where there are two separate problems with the bike. If that ever happens to you, don't walk under any ladders, and watch out for black cats.
Make sure you check audio with the radio playing some music, and check with more than one source if possible, such as AM/FM, and the aux input.
As with many audio problems, no audio from the external speakers can be caused by a problem in the bike or a failure in the radio. There are a number of tests that need to be done to narrow down the cause of this problem. Despite how complicated Factory Service Manuals make this task, you will be amazed at how easy it actually is.
Keep in mind here that virtually anything in the audio path can cause no audio, but in 99.9% of cases, the problem is with the power amp outputs. Most failures in electronics happen in the circuits that are exposed to the outside world. We will be troubleshooting for a power amp failure in this article.
It may seem pointless to just test for a blown power amp when there is so much other ciruitry in a radio that can cause no audio, but there is a reason to the madness, and the key is the symptom. Except for the power amps, the entire audio path in the radio is shared between headset audio and external speakers. If any of those circuits fail, you would lose audio to headsets AND external speakers. This is why being observant to symptom details is so important.
Before digging into this problem, check with multiple sources, such as FM and a music player plugged into the aux input to make sure there is not something wrong with one of your sources. Switch to headset mode temporarily to make sure audio is there. If anything checks different from the title of this article, you problem is somewhere else.
Some technical information is needed here to help you understand what happens when you have no sound. The external amplifier in the GL1800 radio contains protection circuits. The protection circuits shut down the amplifier in the case of a shorted amplifier output to protect the speakers. This also prevents a high current situation that could be a safety hazard. The protection circuits will also shut down the power amp when they detect a shorted speaker or wiring that can damage the amplifier. This means that two completely different problems can cause the same symptom.
It is important to understand that even if only one channel is affected, the protection circuitry will shut down audio to all four speakers. Your job in troubleshooting this problem is to find out whether you have a speaker or wiring problem, or a blown amplifier.
The most common external cause on the GL1800 is pinched speaker wires near the trunk hinges. Closely inspect the harness in this area for damage. Also, If you just replaced the front speakers with aftermarket drivers, check to see if the speaker terminals are facing toward the instrument cluster. Sometimes, oversized speakers can short out to the bolts on the inside of the cabinet, which will shut down the amp. If you remove the speakers and your audio comes back, you have found the problem. This can be easily resolved by remounting the speaker turned 90 degrees. Don't be OCD about this. Logos on speakers don't have to be right side up.
If you don't find any damage to the rear speaker harness, completely eliminate the rear speakers and wiring as a cause by removing the seat and unplugging the 4 pin rear speaker connector. It is located inside the rubber boot behind the relay box. Then check to see if you get audio to the front speakers. This is much easier than removing the rear speaker pods to disconnect the speakers. If you do get audio, then you have a problem with your rear speakers or wiring. Keep in mind that even though the radio protection circuits work quite well, nothing is perfect. A short back there could blow the power amp. So be prepared to have two possible problems. It often depends on how high the volume was when the short occured.
At this point, if you still have no audio, you have made a pretty good case that the amp is blown, but you haven't actually proven it yet. I highly recommend continuing with the next test, which will prove it either way beyond any doubt.
With the rear speaker connector unplugged, turn the ignition to accessory, turn the radio on, and turn the volume all the way down. The audio source does not matter. Just make sure the radio mode is set for external speakers. Attach your negative meter lead to a known good chassis ground, or the battery negative terminal. (don't use a painted surface as a ground.) Set the meter for DC volts. If it is not autoranging, select a range of about 20 volts. Measure the voltage at each of the 4 pins on the connector that goes up to the radio, not the one that goes back to the speakers. Even though you want to try to avoid letting the probe slip and momentarily short across pins, don't be nervous about it. Current at the connector pins is quite low with the volume turned down. Damage is unlikely.
Just because things always have to be confusing, the voltage you should get will depend on what type of amplifier your radio has. But don't worry, you don't really need to know the type. There are only two possible correct voltages. You are more interested in the pattern of the voltages than the actual values. With a good amp, you should measure either 3.0 to 3.5 volts, or about 5 to 6 volts DC at each pin. If even one pin measures near 0 volts or near 12 volts, you have a blown amplifier. Measure any 0 volt measurement a few times to make sure oxidation of the pins isn't affecting the measurement.
Based on the pattern of failures I have seen over the years, usually only one pin measures wrong. The rest will all measure correct. Every great once in awhile, there will be a complete failure of the amp and you will read either 0 volts or 12 volts on every pin, but that is not as common. If you do measure 0 volts on every pin, double check your ground lead, and make sure your meter is working by checking the voltage at the battery. (A good technician is always frequently testing and verifying his test equipment.)
I have found that in nearly all cases, it is the rear channels that blow, so you can usually stop measuring at the rear connector. But you can also check the front speaker wires as well. To do this, you must disconnect at least one wire from each front speaker, just as you did for the rear outputs by unplugging the connector. The resistance of the speaker voice coils can mask a bad voltage. Check the voltage on each of the 8 speaker wires to make sure they all measure 3.0-3.5 volts, or 5 to 6 volts.
A little side note is appropriate here. For 2001- 2002 owners only, the voltage you measure is actually a good way to determine whether you have one of the low power, high distortion amplifiers that can benefit from my amp upgrade. If you measure 3 to 3.5 volts, you have one of the low power radios.
Before I end this article, I would like to share one last bit of information for those who are just curious. (Aren't we all?) Some of you who have worked with audio a little bit may be wondering how there could be 6 volts on the speakers. You were taught that DC voltage on a speaker is a bad thing, and that is correct. In reality, there isn't any voltage across the speakers. The voltage you are measuring is referenced to ground. In a conventional amplifier, the negative lead is grounded, and the positive lead is driven by the amplifier. You must measure 0 volts in a sytem with a grounded negative lead. But in an amplifier like this, the negative lead is not ground. Head units typically use bridged power amps for each channel. The negative lead is also driven by an amplifier. In other words, there are two amplifiers for each channel. Each speaker wire is driven 180 degrees out of phase with the other, which helps give more power from a 12 volt battery.
If you have 6 volts on one speaker lead, and 6 volts on the other lead, what is the net voltage between the speaker leads? That's right. zero volts. If you were to measure the voltage across the speaker leads on a working amplifier instead of measuring to chassis ground, you would measure zero volts, which is exactly what you were taught. When troubleshooting however, measuring across the speaker leads is not a reliable way to check for blown outputs. For example, if both speaker leads measured 12 volts to ground, the voltage across the speaker leads would be 0 volts, which is what you want. You could be fooled into thinking the amp is ok, when in fact it has a problem. Always measure the speaker DC voltage to ground, not across the speaker leads. That means you have to make 8 voltage checks for a 4 channel system.
One last thing to mention. For future reference if you are ever working on a non-Goldwing audio system; There are a number of different amplifier types out there, and not all of them can be diagnosed with this method. You have to know the type of amplifier you are working with before you go in and start taking voltage measurements. As a general rule of thumb, this method will usually work with head unit amplifiers, and many low power external amps such as the 06-10 GL1800 amplifier, but not with high power aftermarket amplifiers.
Troubleshooting no audio to the speakers on the later model GL1800's is a little different than the early Goldwings because of the external amplifier used with the Premium Audio System. The symptoms can be a little different, but the same basic troubleshooting principles for the 01-05 models apply.
Symptoms for the external amplifier are generally one or two speakers don't have audio. You will rarely have all four channels out. This is because each channel has its own protection circuitry.
The first step if the rear channels are out is to check for a pinched or cut rear speaker harness at the trunk hinges. Yes, this problem still exists on the later models, only this time the poor routing was done at the factory.
As with the early radios, each speaker lead has to have approximately 6 volts DC on it, when measured with the negative meter lead attached to a known good chassis ground. Finding a good point to check the voltage is a little more difficult with the external amplifier. The Honda Service Manual suggests testing at the amplifiier connector, but it is not really possible to backprobe these wires because it is a waterproof connector. You may have to actually remove the rear speaker pods or front speakers to access the speaker wires. When you do this voltage check, at least one wire from each speaker you check must be disconnected. Otherwise the resistance of the voice coils can give false measurements. If you find a speaker wire that does not have 6 volts on it, then the amp is blown. Also, make sure the radio is in external speaker mode when testing. The amp is turned off when you are in headset mode.
If you are missing all four channels to the speakers, it is less likely that the external amplifier is the cause. The radio itself may be the problem, Make sure you check multiple sources and check your radio settings before condemning the radio.
The same tests can be done on the 06-10 radio audio outputs as the 01-05, but again, the problem here is that the connector between the radio and amplifier is a waterproof connector that is not easy to backprobe. I have not had the opportunity to work on a late model bike yet. (My bike is an 02) If I come across good test points, I will add them to this article. If someone reading this has done it to there bike, please email me so that I can add it.
Let me first get a pet peeve out of the way. The emphasis in the description here is intentional. I often have problems with customers describing intercom and headset symptoms, mostly due to slang used among riders, most prevalent on Internet forums. The terms intercom and headsets are loosely used interchangeably. The distinction is important because both symptoms require entirely different troubleshooting steps. I have sent customers in the wrong direction a number of times because the symptom was described wrong.
Now that that is out of the way;
When your Intercom doesn't work, you first have to determine whether it is a microphone problem or a headset speaker problem. If you can play music through the headsets, but the Intercom doesn't work, this symptom indicates a microphone problem somewhere. The microphone circuits are wired similar to the headset circuits. There is only one mike Pre-amp in the radio, and the audio splits off to each headset. The rider hears everything that the passenger hears. The troubleshooting steps for a microphone problem are similar to a headset speaker problem, with the exception that you have to put the radio in Intercom mode this time.
Turn all music off to make sure that the Intercom Mute does not interfere with the test. Make sure the Intercom is turned on, and check the Intercom Volume setting by pressing the left knob on the radio. Use a minimum setting of 10 for this test. With a verified good headset hooked up to either driver or passenger connector, speak into the headset. If you don't hear your voice, hook up to the other headset connector and retest. If you can hear your voice in either driver or passenger position, the radio is ok, and the problem is in the bike. The connector where you can't hear your voice is where the problem is.
I have yet to see a failed microphone circuit in these radios. In the vast majority of cases, the cause is one of the headsets or lower cords at fault. Less common, but possible is a problem in the bike's wiring. Blame the radio last. But always test first. Don't replace expensive headsets only to find later that you have a rare one of a kind radio problem.
This one often lures people in the wrong direction, and you will be surprised at some of the things that can cause a dead radio. There are a number of possible causes for this, and most of them are not serious. It should be understood that if you have any radio functions showing on the display at all, such as the speaker or headset icons, then the radio is NOT dead! Go back to the Index and pick the correct topic.
You don't have to follow the troubleshooting steps in this section in the order listed. I recommend that you read through the topic and follow the progression that makes most sense to your situation.
1.. Check the fuses. There are two of them and they both must be good for the radio to work. Labeling and number location might be different depending on the year of your bike. On the 01-03, they are labeled Audio/ACC and Battery. The fuse numbers are 21 and 22. Do not rely on visual inspection. Check the fuses with a DMM on the Ohms scale by pulling the fuse and checking for continuity. You can also check for voltage on both sides of the fuse if you have probe tips that are pointy enough. The ends of most fuses have tiny holes on each corner. Put your ground lead on a known good chassis ground or the battery negative post. The Battery fuse is hot at all times. The Audio/Acc fuse is only hot with the ignition on. You should measure voltage on both sides of the fuse. If you have blown fuses, read the Blown Fuses topic on how to resolve the problem.
2. Do you have one of the mp3 adapters that plug into the CD input? These adapters communicate directly with the microprocessor in the radio, and can cause it to lock up in certain situations. This is a design fault in the mp3 adapter, not a problem with your radio.
The first step in troubleshooting this is to remove the seat and unplug the mp3 adapter from the CD input connector. Check to see if the radio works. It often won't if the radio is completely locked up. Next, disconnect the negative battery cable for about 15 minutes. When you reconnect, make sure the ignition is off and make sure you get a solid connection right away. Don't allow the ground lug to lie loosely against the battery post or make any sparks while you tighten it down. The constant making and breaking of the connection can cause voltage fluctuations which can prevent the radio from resetting properly.
If the radio now works, turn off the ignition and try plugging in the adapter to see if it works. The most common cause of this failure is from the BikeMp3 units. If you hit the A-Sel button while in CD mode, you will lock up the radio every time. But the problem can be caused by any brand of adapter for a number of reasons.
3.. Stuck buttons. Yes, stuck buttons can cause your radio to be dead in certain situations. If the radio was turned off or if you attached the battery cables while a button is stuck, the radio will appear to be dead. Refer to the section Buttons Don't Respond When Pressed for info on this problem. By far the most common stuck button is one that people never think of. If you have a passenger audio controller, check to see if the Push to Talk button is stuck in the down position. This button often jams when removing or re-installing the seat. it will kill all audio functions.
This may seem like a cut and dry problem, but it's not. The two fuses for the radio power more than just the radio, and any of them can be the cause of a blown fuse. I have had a number of blown amplifiers in radios that were a dead short to ground, causing the fuse to blow. And i have seen cases where people have installed the wrong battery and hooked everything up backwards, which can blow parts in the radio. But this problem still needs some troubleshooting to make sure your radio really has a problem.
The battery fuse to the radio also powers the following items.
The audio/accessory fuse is only live with the ignition on. It powers the following items
If any one of these accessories develops a problem, it can also blow the related fuse and cause a dead radio.
Don't be tempted to remove the top shelter and unplug the radio, and then replace the fuse to see if it blows as a first step. Before doing that, check out a couple of other things first. You may find a problem elsewhere. Why take off the top shelter if you don't have to?
There are a couple of common problems that cause these fuses to blow, and most of them are caused by accessories or improper installation.
If the accessory fuse is blown, this fuse powers the accessory connector under the left pocket, the grip heater connector under the right pocket, and the accessory terminal screws on the fuse box. These are all popular places to attach accessories. If there is a short in the accessory wiring, or if the line was overloaded, that fuse can blow, which will make for a dead radio. Unplug anything connected to these 3 points and replace the fuse. If it doesn't blow, the problem is probably not in the radio.
Under the trunk lid is a connector for a trunk light. Many people use this connector to power things like cigarette ligher sockets for charging devices. This connector is powered by the battery fuse. If your battery fuse keeps blowing, look at this connector as a possible cause.
After all that is done, then you can remove the top shelter and unplug the radio. When the radio has a dead short, it almost always blows the battery fuse. I have never seen a GL1800 radio blown the accessory fuse.
WARNING!!! Do not under any circumstances ever replace a blown fuse with a higher value fuse, even as a quick test. If anything, use a lower value for testing. Using a higher value fuse can cause serious damage to your bike and a possible fire.
It is not uncommon for a customer to report a symptom of "Dead" when all the buttons are unresponsive and there is no sound. But if radio functions are showing on the display, it is not dead. This is an important point to make so that the correct troubleshooting steps are followed. To use an analogy, an unconscious and unresponsive person is not dead if their heart is still beating.
A little technical information about how modern digital controls work will go a long way towards helping owners understand what happens when buttons stop working.
Like many of today's products, most of the controls on the GL1800 radio are momentary switches. They are on when you press them, and off when you release. These controls are arranged in what is known as a key matrix and they all have a direct connection to the radio's microprocessor. A key matrix simply allows many functions to operate a device with fewer wires. Instead of needing 40 wires for 20 switches, you might need only 5 wires to the microprocessor. A key matrix uses combinations of the available wires to let the microprocessor know which button was pressed.
The second, and more important thing to understand is that a microprocessor can only process one input in a key matrix at a time.
Knowing that, what do you think would happen if one button became stuck in the on position? It would cause all the buttons on the radio to appear to be dead. Any button that controls the radio, (except for the mute button) can cause this. Your mission in troubleshooting this problem is to inspect every single audio switch on the bike to see if any of them appear to be mechanically not functioning properly. Check all the faceplate buttons to see if any of them are stuck and don't pop back up. Check the handlebar controls, especially the CB PTT switch. But the next one is the one everyone forgets to check.
If you have a passenger audio controller, the most common button to get stuck on the GL1800 is the passenger PTT button. It often sticks after servicing the bike. The seat presses on the button and jams it.
If any of the radio faceplate buttons are stuck, see the topic on Sticking Radio Buttons.
Ok, this one is kind of obvious that the problem is in the radio itself. But what is wrong and how do you fix it?
There are typically two possibilities here. The first is that you have debris or dried up soap in between the buttons and faceplate. The second is that the rubber keyboard membrane has collapsed. The membrane has raised nipples under each button that compress when you push a button, then push the button back up when you release it. If a nipple collapses, the button won't pop back up. You can't tell without taking the keyboard apart which problem you have. They feel the same. I have a limited supply of membranes in stock. Because of the high cost of this part, it is NOT included in my flat rate repair. The membrane costs an additional $65 on top of the flat rate repair. I know. Ouch!
Do not force a stuck button. If you are on the road and a stuck button is keeping the radio from working, you can try to gently pop it up with something that is not metal, but be careful. The plastic is soft and easily damaged. If you get it popped up , leave it alone until you have a chance to repair it properly.
The rubber keyboard membrane also serves a second function. It protects the keyboard from water that get down in between the keys. I have had a few collapsed nipples that were actually torn. This allowed water to reach the keyboard and damage it. Again, water damage is not covered under my flat rate. Water damaged boards are not repairable and must be replaced. As you can see, what seems simple can actually get quite expensive, especially if you ignore it.
If you are reasonably mechanically inclined and good at putting back together what you took apart, you can clean a keyboard yourself. There are no springs that will pop out or anything. Just remember the order you took everything apart. But many owners don't want to attempt this. That's ok. I can repair it for you. Better yet, send your radio in for the upgrades if it is eligible, and the keyboard will be torn apart and cleaned for free. This is a non-advertised maintenance service that I do on every radio that needs it before it leaves the bench. How can you beat a deal like that?
All you have to do is remove the 4 black screws from the faceplate and lift it off the radio. Then remove the screws holding the circuit board in place.
Most of the time, it is sand in between the buttons that causes them to stick. Sand does not compress like dirt does. But dried soap from washing can cause it too.
The only caution needed here is for two parts. Do not touch the gold circuit board contacts for the switches, and don't touch the black carbon on the tips of the nipples. Skin oil can increase resistance. Do not clean these points with anything either. The carbon and the coating on the gold contacts comes off easily. Stick with cleaning the black plastic pieces and you will be fine.
You can check the nipples for a problem by pressing on them. A bad nipple will be weak and want to compress to the side instead of straight down. Compare good ones against one that you suspect is bad. If you can't tell, when you put it back together, you will find out quickly enough if it was dirt or a collapsed membrane.
Trying to track down excessive leakage current that drains the battery can be time consuming on any vehicle. It also requires a little more than a basic knowledge of electronics than most troubleshooting because you have to be highly familiar with how the current function on a multimeter works. It is also potentially hazardous for a beginner.
There are many things that can cause a battery to drain. It is beyond the scope of this article to show how to find all types of drains. These steps are intended to help you find out if your radio is the cause. The methods for finding a drain other than the radio are similar.
There is no easy magic test that technicians do to solve problems like this. You simple have to isolate systems until you expose the problem. You can get lucky and find it first time, or it can take many attempts.
I am going to start off this topic with basic things that a novice can do. If that does not locate the problem, we are going to get into a few things that may require you to get some help, depending on your level of experience.
One thing that needs to be stated here is that, just like car batteries, motorcycle batteries are not deep cycle batteries. They do not like to be deeply discharged. The thin, delicate plates on a non deep cycle battery suffer some amount of permanent damage each time the battery is deep discharged. This damage is slight however, so 2-3 times will probably not cause enough degradation to make a difference. Just don't do continuous testing by seeing if your battery dies overnight. And until the problem is fixed, disconnect the negative battery cable when you are not working on the bike to stop the battery from draining.
There are a few simple questions that have to be answered whenever you have a dead battery.
Your answer will be yes to one of those questions. And until you answer questions 1 and 2, don't even bother with question #3. Troubleshooting excessive current draw can be very time consuming depending on how deep you have to dig.
If those two tests check out, we have to assume that something is drawing too much current. Now we just have to find it. I will show two methods here, a simple method, and an advanced method with a multimeter.
Leakage test Simple Method
If you are not confident in your abilities with measuring current with a multimeter, you can still do some basic tests that will just take a little longer. This method works pretty good if you are trying to isolate a single specific circuit. But if the problem is becoming elusive, you are best off using the advance method at the end of this article.
The first thing I recommend is looking at what accessories installed on your bike that can cause a drain. If you have one of the mp3 adapters that plugs into the CD input connector, these are highly suspect. Unplug it from the CD input connector, disconnect the negative battery cable to reset the radio, and hook up the cable after 15 minutes. If you have a CB, unplug the 3 pin power connector. (Unknown water damage to the CB can cause current leakage.)
Look at any accessory that you have that connects directly to the battery and disconnect it. This includes heated clothing controllers.
Make sure the battery is charged, and measure the battery voltage about 5 minutes after removing the charger. Write the voltage down and let the bike sit. Come back every few hours and take a voltage measurement. If the battery voltage drops under 12 volts on a fully charged battery in a short time, the components you disconnected are not the cause.
Leave those accessories disconnected and remove the battery fuse from the fuse block. On the 01-03 bikes, this is fuse # 22, which is a 20 amp fuse. On a 2008, it is fuse 31. Check the label on the cover of your fuse block for the proper fuse for your bike. Also, if you have a 2006-2010, pull the power amp fuse as well. it is the large fuse at the bottom of the fuse block.
Do the same test again. Charge the battery and then write down the voltage after the charger is disconnected for 5 minutes. If the voltage still drops, the problem is not in your radio and you have something else wrong with your bike, such as a stuck relay or bad ignition switch.
Don't get fooled by these measurements. It is normal for the battery voltage to settle somewhat after charging. But it should not get very much under 12 volts.
Leakage Test Advanced Method.
For liability reasons, I have decided not to describe how to set up a meter to measure current. I cannot risk someone making a mistake, causing damage and blaming me for it. If you don't already know how to do this, you should not be attempting it. This is a potentially hazardous measurement. Your meter is actually inserted into the bike's wiring. Connecting the probes to the wrong test points can put a direct short across the battery posts. You accept all risk in performing this test. Information is available elsewhere on the Internet if you want to learn this measurement. I recommend practicing on something that uses a power supply with lower current capacity before tackling a motorcycle battery.
Checking for leakage should be done by disconnecting the negative battery lead. This is much safer than using the positive lead. The meter will be connected with one lead on the negative battery cable, and the other lead on the negative battery post. Set your meter to read milli-amps, and DO NOT turn on your ignition at any time while the meter is connected.
The Honda manual states that leakage current should be somewhere around 7 milli-amps. This is a good starting point, but keep in mind that if you have accessories installed, current could measure up to about 15 ma. or so. This is normal and will not kill your battery. When the battery dies within a day or so, the current draw will measure around 100ma or higher. If the current measures high, start pulling fuses one at a time until the current drops. The same thing applies as with the simple method. All accessories such as mp3 adapters should be disconnected from the bike since they might be connected to the same fuse as the radio.
Don't get the decimal place mixed up. Remember that .2 amps is 200ma and .02 amps is 20ma Most meters will actually measure in milli-amps, so you should not have to convert between amps and mill-amps. Also keep in mind that inexpensive meters might have a hard time measuring current accurately at this low of a reading, so don't be too picky with your readings. This problem is rarely borderline. It is either normal, or very high.
Once in awhile, a problem happens with the audio ground for the Aux input. The problem will exhibit a very specifc type of distortion. The audio will have the distinct sound of an echo, and there will be virtually no bass. The volume level will be noticeably lower as well. The reason for this odd behavior is that when the audio loses its ground, the left channel will pick up its ground through the right channel, and the right channel will pick up its ground through the left channel. The wider the stereo separation, the worse it sounds. Any similarities in the stereo sound coming through the left and right channels tends to cancel each other out.
If your distortion does not match all of those symptoms, then the problem is elsewhere. Try lowering the volume at your mp3 player to see if the sound quality improves. it is possible to overdrive the radio inputs with high output mp3 players. Dirty connections on GPS cradles are another possibility.
The AMB function can also cause some odd behavior. I always recommend that owners turn this function off while troubleshooting poor sound. Certain types of music react badly with the Ambiance function.
If you suspect a bad ground problem, first turn off the AMB feature on the radio. AMB tends to muddy the sound, making it difficult to diagnose.
I have seen failures in the radio cause this symptom, but it is less common. The scenario here is a device that is plugged into the Aux input and is getting it's power from the bike. If the device's power ground is connected to a bad ground, or if the ground connection fails, many devices will try to use the Aux signal ground as a power ground. (Power grounds and signal grounds are not always isolated.) Since the aux input ground was not designed to handle power, the excessive current blows out the circuit board trace for the aux ground. The only way to fix this is to send it out for repair. Fortunately that problem is rare. Most of the time it is one of the connections in the aux line.
The best way to attack this problem is to go for the easy stuff first, and work your way to the most difficult fo repair problems. The first thing to do is clean the 3.5mm headset style plug in the left pocket. Drip some WD40 or contact cleaner on a paper towel or scrap rag and rub the contacts until they are clean. You usually cannot see the thin layer of oxidation that causes a bad connection . Note that this can also be caused by the jack in your player or GPS. Try substituting with another player to see if the problem goes away.
If you are not lucky enough to have a bad headphone plug, then the problem is probably being caused by the white 3 pin audio connector under the left pocket. The connector is located in the rubber boot. Pull this connector and clean it with some WD40 or contact cleaner, and retest. You can even flex the connector slightly to see if the problem is intermittent.
If you still have not solved the problem, things begin getting more difficult to fix. Sometimes the connector actually goes bad. The area where the wire gets crimped onto the connector pins can become oxidized and lose its conductivity. You can hope it is the 18" long aux cable that is bad and order a new one, but if it is the bike side connector, the only solution is to either pull the pins out and re-crimp or solder, or just cut the connector off and replace it. Working with the bike side connector is not easy with the fairing on. If you are not good with working with tiny wires in a tight spot, try to find a friend who has experience. Making a mistake will just force you to cut the wire again, making it even shorter, and that much more difficult to repair.
You might think that my answer to this question would be to get the amp upgrade, but not so fast. Before wondering if you need the amp upgrade, you have to ask yourself, how severe is the distortion? The radios with the high distortion amplifiers don't sound very good, but if your distortion is severe, you probably have a problem with your audio system, and until that is fixed, getting the amp upgrade won't do you any good.
I get this question quite often in emails from customers. I probably should tell you right from the start that severe distortion is almost certainly not a problem in the radio. It is not impossible for a radio to distort, and you certainly could have an unusual problem. But with this symptom, the radio is the very last thing to blame. Radio failures almost always result in no audio somewhere.
With a stock system, distortion is usually caused by the speakers themselves. The stock speakers have cheap treated paper cones that quickly lose their stiffness. And even aftermarket speaker succumb to the elements. Most aftermarket speakers are only water resistant. That means that they should not see direct contact with water, and we all know that never happens on a motorcycle. Sometimes speakers are just not very high quality, or are just a poor match for our cabinets. (The Polk db501 is a fully waterproof marine rated speaker, not just water resistant.)
Aftermarket amplifiers are another cause. People are often drawn in by no name amplifiers because of their small size. They advertise high power in a small package, and many owners figure that it is worth a chance. You never know when you will come across the next great Goldwing accessory. But more often than not, these amplifiers are actually low quality and do nothing more than add to the distortion. It is also possible even with a high quality amplifier that the input level control of the amp is set to high. This will overdrive the inputs to the amp and cause distortion.
This is a very common problem on the GL1800, and is usually caused by a classic ground loop. It only happens when you connect an audio source that is powered by the bike's battery.
This is not a defect in the radio or the bike's wiring. It is caused by a combination of many factors. Ground loops are a complex subject. It is beyond the intent of this website to go into a full technical explanation.
The only solution to this problem is to install a ground loop isolator. They are available from many electronics sources such as Electrical Connection and Crutchfield. Electrical Connection has one version that replaces the existing aux cable and plugs right into the 3 pin aux connector under the left pocket. Others plug in in-line with the existing aux cable. When you shop for a GLI, make sure it has 3.5mm plugs on both ends. Radio Shack sells them, but the last I saw, they only had RCA jacks.
Before we dig into this problem, please note. Do not email me for help on alternator whine issues. I cannot offer any suggestions beyond the common fixes that you read here. Alternator whine can be a very difficult problem to troubleshoot, with many causes, and many solutions. It is for the most part something you have to be at the bike to diagnose if the bike requires troubleshooting beyond the basics shared in this article.
Alternator whine is often a case of trial and error, and can be very frustrating, but hopefully I can send owners in the right direction with some basic information and common causes.
The first step in solving this problem is to thoroughly operate every function of the audio system, noting every little detail you can gather. Items that may seem insignificant can actually be major clues. Subtle symptoms can often lead directly to the cause.
For instance, if your noise is only present with the aux input, you probably need a ground loop isolator. If the whine only happens when you engage the cruise control, you will have to install an RF shield around the cruise module.
For noise that is present with all sources, bad grounds are the most common cause. The most likely culprit with the GL1800 is the main ground under the fuel tank. This ground is the return point to the battery for not only the radio, but also most of your bike’s systems. Remove the negative battery cable, remove the fuel tank, and re-work this ground. Scrape or sand any powder coat off that area of the frame, run a tap through the mounting hole to clean off any powder coat, and re-install the ground wires and bolt.
Some people have taken the extra step of running a ground wire from this point directly to the battery. A word of caution is needed about running a ground wire however. Even though there is normally not a lot of current flowing through this ground, if a high current ground return ever did go bad somewhere on the bike, such as the G1 ground, the load will try to use your added ground as a return path to the battery. For this reason, any secondary wire that you add must be able to handle the full current capability of the bike. Do not use anything less than an 8-10 gauge wire for this duplicate ground path. (It probably should be even heavier than that.)
The extended ground wire fix does permanently solve many noise and whine issues, but for liability reasons, it is my position to not endorse it due to the potential hazard, no matter how unlikely the hazard is. While it may seem like just an innocent piece of wire, it is not. When you do this, you are altering the OEM wiring design by supplying a duplicate ground path from the frame to the battery. I would feel more comfortable with this fix if I were to actually test the current demands of the bike's electrical system so that the correct, safe gauge of wire could be determined, but I have not done that. I do acknowledge that the likelihood of a failure of the type I am concerned about is very low. It just isn't low enough for me.
As an alternative, the correct, by the book method for doing this fix would be to completely remove the ground wires from the G2 ground under the tank and splice them to a ground wire that runs directly to the battery. It would serve the same purpose, with the exception that it would isolate your ground wire from the hazards I am concerned about. It will remove the frame to battery ground path that can cause safety problems. I have not tried this however, so I don't know how well it would work. In theory, it should work, but when it comes to alternator whine, theories are just theories until you prove that they work.
For those that are wondering; Yes, I am extremely safety conscious when it comes to electronics. I don’t believe in throwing caution to the wind, and I don't believe in "It's good enough". I have built a repuation of trust among my customers that I would never suggest anything that could put them in harm's way. But I also understand that not everyone agrees with my stance on this mod, and everyone's risk tolerance level is different.
So why am I even sharing this if I don't endorse it? It has become a fairly popular mod over the past few years, with at least one servicer advertising it and performing it in his shop. I have received a number of emails asking me about it, so I figured I would share the information and let everyone know where I stand on the issue What you do with that information is up to you. If something does go wrong, nobody can come back to me and say I didn't warn them.
I am not claiming to be the final word on this subject, It is not uncommon to see design opinions disputed among industry professionals. This is one of those cases. Electronics always carries at least a small amount of safety risk. It's just the nature of the beast. It may very well be that I am being overly cautious on this subject.