'80 650 LTD brake light problem

Hey everyone, I recently swapped the stock tail light on my 650 LTD for a smaller bates style light. Everything was wired correctly, and until yesterday the light was functioning exactly as it should. However, upon getting ready to ride last night, my friend pointed out that the light was out, so we shook a couple of wires around and the light came back on, but now the brake light stays engaged, even after unplugging both of the brake light switches from the rest of the wiring. I've followed the wires from the tail light as far as I can without having to unwrap everything, and can't find anything unplugged or frayed, wondering if anyone else has had this problem in the past and if they found a solution

Just an update, I've unplugged the tail light and it seems like there's actually no running light at the moment. Not sure if that means that the current just can't get through until the wire running up to the brake pedals is connecting, or if I've just somehow blown the running light.

First check your fuses to make sure you havent blown anything while fiddeling around with it then check the wiring diagram to see if you have a diode coming from the tail light,going up to the running lights ( or other way around). If so,that could be on the fritz .Or, bad connections in the loom (there are quite a few OEM splices in there).Either one of these will mean unwrapping the loom for a bit ( say from the tail light/indicator connection block,up until around the rear brake switch.To start with) to find the problem.
Another thing to check,while youre in the fuse box, is that the wires are well soldered in. Sometimes they look ok but on closer inspection you can find the solder has broken away or the wire is only held on by a couple of strands.
My tuppence worth. Hope it helps.

Thanks man. In between my turn signals/hazards messing up in the handlebar control and wanting to remove the mass of wiring left over, this may be the final straw to start over and rewire the whole sumbitch; I've had electrical problems with it since I got it a year ago

Rick418 wrote: Hey everyone, I recently swapped the stock tail light on my 650 LTD for a smaller bates style light. Everything was wired correctly, and until yesterday the light was functioning exactly as it should. However, upon getting ready to ride last night, my friend pointed out that the light was out, so we shook a couple of wires around and the light came back on, but now the brake light stays engaged, even after unplugging both of the brake light switches from the rest of the wiring. I've followed the wires from the tail light as far as I can without having to unwrap everything, and can't find anything unplugged or frayed, wondering if anyone else has had this problem in the past and if they found a solution

It seems that you have accidentally, uncovered or exposed sections of wire and shorting your "running lights" to your brake light circuit which is why your brake light is on even while you've unplugged both front and rear switches. This could be happening from any number of other powered circuits in the main loom but since you were focused on the tail light, it's most likely right in the rear of the bike over/thru the rear fender area unless you jostled the entire main loom it's unlikely a new short has been created anywhere else.

Another thing to check is that the twin-element bulb in the tail light okay and is not accidentally installed backwards - making the normally brighter brake element illuminate with "running lights" and masking the running light element from being seen.

Another thought I just had,concerning the brake lights. When you disconnect them from the lever/pedal be aware that the front switch operates in the reverse to the back switch,the back switch you need to pull to operate while the front ,you need to push. Meaning that if the frontswitch is seperated from the lever,it will,in effect,be constantly 'on' . Lighting the brake lamp.
This had me confused for a bit until I figured it out.