1980 GS1100E Brake light?

[liloaty]

Hey guys, I hope someone has some ideas for me because its starting to warm up outside and I cannot get this stupid brake light fixed.

The bike was laid down last season by a friend :x and since then the brake light will not come on. On the indicator panel it says the tail light and brake light are hosed BUT the tail light still works! It's just the brake light and it will not come on with the pedal or handle switches. What should I look for here? I checked the bulb, its good. I figured the taillight and brake light shared a common ground so I haven't check it yet, but if I should, where the heck is it?

If you guys need anymore info let me know. Thanks a ton

EDIT: Also, I need to find a new signal generator cover and Google is turning up a big fat nothing. If anyone knows where to find one, that'd be great.

 

[Steve]

It could be a ground.

You say the tail light works, Does it stay on when the brakes are activated? If the tail light goes OFF when the brakes are applied, you have a bad ground to the light assembly.

Your best friend here is going to be a test light or a meter. Either will work, but the light is quicker and easier. First, make sure all the fuses are good, especially the second one from the top. (This fuse also powers the turn signals and horn, so see if they work, too.) If the fuse is good, make sure you have power to the brake switches. There are two wires that go to each switch (front and rear), one wire should be hot when the key is on, the other one will be hot when the switch is activated. The next place to check is the connection under the seat. On some bikes it's closer to the battery, on others it's laying on the back fender, but there is a connection there. The last place is the bulb socket in the light. While you are looking at all these connections, make sure they are clean and tight, and you should be good to go.


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[liloaty]

It could be a ground.

You say the tail light works, Does it stay on when the brakes are activated? If the tail light goes OFF when the brakes are applied, you have a bad ground to the light assembly.

Your best friend here is going to be a test light or a meter. Either will work, but the light is quicker and easier. First, make sure all the fuses are good, especially the second one from the top. (This fuse also powers the turn signals and horn, so see if they work, too.) If the fuse is good, make sure you have power to the brake switches. There are two wires that go to each switch (front and rear), one wire should be hot when the key is on, the other one will be hot when the switch is activated. The next place to check is the connection under the seat. On some bikes it's closer to the battery, on others it's laying on the back fender, but there is a connection there. The last place is the bulb socket in the light. While you are looking at all these connections, make sure they are clean and tight, and you should be good to go.


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Thanks for the solid advice. For the connection under the seat, I believe mine is laying under the fender and it's a rats nest of wires in there, am I looking more for a power or ground connection?

Thanks

 

[Steve]

... am I looking more for a power or ground connection?

Eventually you will need to check both sides. Start by verifying the simple stuff. Remove the bulb from the socket. Clip your test light to the negative side of the battery. Turn the key on (so the tail light would come on), touch the two terminals in the tail light socket to determine which one is tail, which one is brake. Keep the test light on the brake terminal, activate one of the brakes. Does the test light come on? If it does, you have now verified that you have power. If it does not, check the fuses to make sure that you have power on both ends of all the fuses when the key is on, then move through the rest of the harness to the brake switches. Move the test light clip to the positive side of the battery, touch the test light to the tail light socket. If it lights, you have just verified a good ground, and your problem is likely a bad bulb. Most tail light assemblies have a separate ground wire because they are rubber-mounted. Follow that wire back to where it attaches to the chassis, checking every connection along the way.

Just follow a systematic approach and you will soon find the problem.


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[liloaty]

Thanks so much for the informative reply. Hopefully I can solve this problem tonight

 

[liloaty]

To edit my first post, the taillight is not working, its actually the license plate light that works. Sorry about that

OK I did some more testing and I think I'm even more confused. I bought a test light that has 2 LEDs, there is an alligator clip and a pointed end. When the alligator clip is on a ground and the pointer is on a hot terminal the red LED goes on and when the connections are flip flopped it goes green. Now for the strange part:

The outer shell on the light is the ground, the two prongs are the hot terminals for the light. Both light up when the pointed end is on the terminals, but only one gives me light when the pointed end is on the ground.

If I put the clip on the negative terminal of the battery and touch the terminals in the socket, I get light. If I hook up the clip to the positive battery terminal and touch the ground on the socket, I get light.

I took the light assembly off the bike, brought it into my apartment and hooked up a power source to it. Striped is ground, red/brown is tail, white is brake light. All systems go there, so now I am assuming its the ground the two share, which really sucks because the wiring is all wrapped up and I have NO idea where it may be grounded. Looks like I'll be pulling the tank tomorrow to go exploring.

I'm stumped.

This is beginning to get a little frustrating

 

[Steve]

I love LEDs as much as the next guy, but I am not convinced that a test light is the proper place for them. :shock:

I have done so much troubleshooting using the method I outlined above, where you might clip it on the positive side of the battery instead of a ground. An incandescent bulb does not care which direction the electrons are flowing, so it is better for determining that you do have electrons moving. The LED-based test light assumes that you will be clipping to a ground and probing the hot wires, so you will have to adapt. To use your LED light, you might have to use a jumper wire to clip the pointy end to the positive terminal on the battery, then use the test light's clip to attach to the bulb socket or other ground point that you are testing.

I have not worked on a bike like yours, but if you lift the seat, you should see a small bundle of wires going to the back. You have already removed the light assembly, how long were the wires that came off with it? Did they plug into the harness over the rear fender or did they continue toward the main harness closer to the battery? I have seen both methods before. You have already identified the striped wire as the ground. Plug the other two wires back into their proper places, use a jumper wire to connect the striped wire to the negative terminal of the battery to see if that helps. If it does, you have a bad ground wire in the harness, so just make a permanent jumper from your striped wire to a good ground.


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[liloaty]

I love LEDs as much as the next guy, but I am not convinced that a test light is the proper place for them. :shock:

I have done so much troubleshooting using the method I outlined above, where you might clip it on the positive side of the battery instead of a ground. An incandescent bulb does not care which direction the electrons are flowing, so it is better for determining that you do have electrons moving. The LED-based test light assumes that you will be clipping to a ground and probing the hot wires, so you will have to adapt. To use your LED light, you might have to use a jumper wire to clip the pointy end to the positive terminal on the battery, then use the test light's clip to attach to the bulb socket or other ground point that you are testing.

I have not worked on a bike like yours, but if you lift the seat, you should see a small bundle of wires going to the back. You have already removed the light assembly, how long were the wires that came off with it? Did they plug into the harness over the rear fender or did they continue toward the main harness closer to the battery? I have seen both methods before. You have already identified the striped wire as the ground. Plug the other two wires back into their proper places, use a jumper wire to connect the striped wire to the negative terminal of the battery to see if that helps. If it does, you have a bad ground wire in the harness, so just make a permanent jumper from your striped wire to a good ground.


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I like the idea of just using a jumper to make a new ground. I'm going to go try that now. I don't like the LED test light either, but its what I had. This one actually doesn't care which way electrons flow however, because there are 2 LEDS inside, each hooked up opposite of eachother.

 

[Steve]

If you happen to touch that light to low-voltage AC, do both lights come on? :-s

I still prefer an incandescent light because it will also show you low voltage with a dimmer light.
If something is pulsing, it will also react quicker than a (digital) meter.


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[liloaty]

Couldnt agree with you more, but when you're in a pinch (go to school in Cleveland, home and tools are in Columbus), you gotta buy what WalMart sells haha

\

If you happen to touch that light to low-voltage AC, do both lights come on? :-s

I still prefer an incandescent light because it will also show you low voltage with a dimmer light.
If something is pulsing, it will also react quicker than a (digital) meter.


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[liloaty]

If you happen to touch that light to low-voltage AC, do both lights come on? :-s

I still prefer an incandescent light because it will also show you low voltage with a dimmer light.
If something is pulsing, it will also react quicker than a (digital) meter.


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Im convinced its never going to work again. I checked the connections up on the front at the indicator panel, and got the tail light portion working. It was a busted fuse holder causing that problem. No luck with the brake light. I tried to take apart the switch and it all fell apart and I have no idea how it goes back together - any help on this would be great. I cannot track down the source of this problem, both wires on the brake switch are about 9V, no matter if the handle was pulled or not.

If I was to take this to a shop, how much would you guys estimate it would cost to repair it?

 

[Steve]

IF they even allow it into the shop, figure on two hours plus parts. Sounds like about $175 to me.

The brake switch is not that hard to re-assemble, as long as you have all the parts. Since the parts in the switch do occasionally go bad, you might want to replace the switch. Last time I looked, it was less than $20 for the switch.


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[liloaty]

IF they even allow it into the shop, figure on two hours plus parts. Sounds like about $175 to me.

The brake switch is not that hard to re-assemble, as long as you have all the parts. Since the parts in the switch do occasionally go bad, you might want to replace the switch. Last time I looked, it was less than $20 for the switch.


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I figured that's what the cost would be. Give me an engine and I'm good to go, ask me to wire anything and I'll cry like a 6 year old girl.

As far as the switch goes, I should replace it but I have no idea how to reassemble it; I found a replacement for about 12 bucks, but it has all the pieces that I have so I'd be back at square 1 trying to install it.

 

[Steve]

Assembling the switch is not so bad. If everything is clean enough so you can see the details, it's much easier.

It has been a while, and I don't remember all the details, but I remember there are two contacts in the bottom plate. There is a brass piece that slides across the contacts to turn on the brake lights. There is a plastic piece that hold the brass piece. I think it has a pin that fits in a hole in the brake lever so that everything moves together. There is probably a spring in there, too, but I would have to examine a picture or take mine apart to be sure. The bottom plate is slotted around the mounting screws. This allows for adjustment for when the lights are activated. I don't remember which way to move the switch, but one way will keep the lights ON, while sliding it the other way can delay activataion until the wheel is fully locked up. You should be able to find an acceptable position somewhere between the extremes.


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[liloaty]

Assembling the switch is not so bad. If everything is clean enough so you can see the details, it's much easier.

It has been a while, and I don't remember all the details, but I remember there are two contacts in the bottom plate. There is a brass piece that slides across the contacts to turn on the brake lights. There is a plastic piece that hold the brass piece. I think it has a pin that fits in a hole in the brake lever so that everything moves together. There is probably a spring in there, too, but I would have to examine a picture or take mine apart to be sure. The bottom plate is slotted around the mounting screws. This allows for adjustment for when the lights are activated. I don't remember which way to move the switch, but one way will keep the lights ON, while sliding it the other way can delay activataion until the wheel is fully locked up. You should be able to find an acceptable position somewhere between the extremes.


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You're a genius...got it back together. Now back to the main concern...the brake light. I've got 4 hours to devote to this tomorrow, if I can't find the problem I'm going to rewire the entire brake system.