Sparking and blowing fuses when using rear brake

misternovice

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Tuesday - riding home. Everything working fine, then stopped for a few minutes. Turned the bike back on, and only the main headlight + rear lights worked. No signals, or brightening of the rear light when lights turned on.

Got home, checked, and a wire cluster in the head lamp had come apart, and a fuse for the lights had blown.

Replaced the fuse box (been putting it off for awhile), and now the blade fuses work great.

Ran through everything to test, and lights all worked, except for the rear brake which dimmed when using the rear brake lever instead of brightening.

I saw some sparks down below, video here
https://goo.gl/photos/m4QQMpWjksp7wWK3A

Electrical is not my forte. I think it might be something lose/worn in that brake signal device pictured, but I don't know how to check that.

Advice appreciated.
 
I think it might be something lose/worn in that brake signal device pictured, but I don't know how to check that.
I think you have it figured.
Not sure if they can be repaired. Might be possible to pop the casing open and look for loose or frayed wires.

Pretty cheap thing to replace though. Local shops or one of the salvage yards might have something.
Maybe call up Jon Armstrong in Surrey or the Bent Bike in Langley.
 
I went over the wiring again today, and before I tried another spark plug fucking with it, I definitely saw smoke coming from the rear brake switch.

Disconnected it for the temp, and everything else runs fine( aside from the right blinkers not blinking unless revving to 2krpm, but that's an existing and separate issue. I hope)


I'm going to call around in the morning and see if anyone has a spare in stock, or else I'll just order one from 650direct.

Would http://www.xs650direct.com/products-55.html the top rear brake switch on this page fit? looks like I can swap out the spring arms, but it should match close enough I figure.
 
I could be wrong here but think you are looking in the wrong direction. My thought is if the switch is sparking it is due to a short in the wiring from the switch to the tail light. If there was a short in the switch itself more than likely the result would be the brake light would stay on.
 
The switch only sparks when activated. I'm wondering if there is a worn out component in the switch that is causing the spring arm to be conducting power away?
 
At a minimum, take the existing switch apart and see what is shorting out. It may be an easy fix. Otherwise replace the switch and then find the next problem.

Old bikes can be challenging to resurrect, but after the first year, it should be smooth riding with minimal issues. The few issues that develop will be quick fixes as you will be familiar with the bike. Or you can sell it for a loss and move onto the next challenge...
 
The switch only sparks when activated. I'm wondering if there is a worn out component in the switch that is causing the spring arm to be conducting power away?

I guess it might be possible if something is shorting out to the rod the spring linkage hook to.

One quick question, Does the brake light work right when using the front brake?
 
At a minimum, take the existing switch apart and see what is shorting out. It may be an easy fix. Otherwise replace the switch and then find the next problem.

Old bikes can be challenging to resurrect, but after the first year, it should be smooth riding with minimal issues. The few issues that develop will be quick fixes as you will be familiar with the bike. Or you can sell it for a loss and move onto the next challenge...



Overall it's been pretty solid.

I'm going to remove the part tonight when I get home from work, and see about taking it apart.

I haven't been able to get it out thus far though, and I haven't found any videoguides to help. May take a bit of force...
 
I guess it might be possible if something is shorting out to the rod the spring linkage hook to.

One quick question, Does the brake light work right when using the front brake?

Yup, the front brake triggers the light perfectly fine when pressed. It's only when the rear brake is activated that things go wrong.

Two things I'm going to check when I get home from work tonight
1. wire together the yellow and brown going to the brake switch, to see if those cause problems when manually activated sans the switch
2. If that connection is good, then it isolates it solely to the switch.
3. Remove the switch, and take apart, see where contact's being made. I imagine this will be evidenced by the burn marks (I saw smoke briefly...)

If It turns out to be the switch, and I can repair it, then dandy. If I can't, then I'm going to wrap the spring attachment in electrical tape to prevent conduction, and I think that should be a temporary fix until I can order in a replacement.

If it turns out to still be something in the wiring, then... fuck.
 
Update - theory confirmed. Brake lights work perfectly when yelow and brown wires connected directly.

Switch removed, but it doesn't look like something that can be taken apart and repaired. Luckily my repair guy has one in stock.

Unfortunately, he closes at 4 today and only reopens on Tuesday. Such is life...
 
Update - theory confirmed. Brake lights work perfectly when yelow and brown wires connected directly.

Switch removed, but it doesn't look like something that can be taken apart and repaired. Luckily my repair guy has one in stock.

Unfortunately, he closes at 4 today and only reopens on Tuesday. Such is life...

OK, so you proved it is the switch so now that one is going in the scrap bin. Perfect time to do a little autopsy on it. If you look at the outer housing I think you will see a couple notches opposite each other at one end. Take a couple small screwdrivers and gently pry down from the end towards the notches. End should pop right off with a little work. There should be a couple copper strips, one on each wire. The rod the spring connect to has contact that shorts between the two to turn on the light. Something is probably broke inside causing your problem but at least you can see how it works and what did fail.

I had to disassemble the switch on my XS650 about once a year due to dirt and moisture getting in switch and causing it to bind. This was a bike rode year round right through the snow and salt in Central NY.

If you really want to ride before tuesday just leave switch off and make sure you use front brake first at every stop!
 
I had this same problem the copper tabs were weak and have way issuing a short. Repaired it with some scraps I had lying around and works great now.
 
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