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help! brake light always on

1K views 10 replies 5 participants last post by  darkthom 
#1 ·
(EDIT, i'm spamming my own post to be able to post pics)

i've read through the other threads and haven't quite figured out a solution yet, so i'm posting, but feel free to direct me to other posts if my search skills were inadequate.

i bought a f650gs twin last week, and i like it, but realized that the brake light is always on. (only reason i know this is i compared the light reflecting off the garage door to that of my other motorcycle next to it) the picture i inserted is that of the rear brake lever and the microswitch next to it. i'm not sure if there is supposed to be something on the lever that contacts the microswitch, but nothing is there.

that being said, i removed the hand lever and the foot lever and actuated both switches by hand and had no change in the tail light output.

any suggestions?

Thanks!

mike
 

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#6 ·
Well, that's that!

The same safety premise is applied to the micro switches (a failure of the switch results in the brake light turning on because the relay is set to do this upon failure.)

Since two switches control the one lamp and broken = on, troubleshooting is going to take some thinking through. A schematic would help. Ideally, you'd be able to isolate (disconnect) one switch at a time and test the other. While the switch is the most likely culprit, we can't overlook the relay.

A test of the two switches would entail removing the connector of each (start with the hand brake, it's the easiest to access) and then completing the electrical connection. This would simulate a working switch (meaning the circuit is closed.) The relay sees an uniterupted flow of electricity from that switch and keeps the light off. If, after testing the hand brake switch the light remains on, do the same for the foot brake. Ensure you keep the hand brake connection closed at the same time.

I hope this makes sense!
 
#7 ·
thanks i was able to test the resistance of the rear microswitch with a multimeter. i inserted two bread twist ties into the plug behind the side panel and it beeped at me, indicating resistance when i activated the microswitch. (i think that means it's good?)

i wasn't able to test the front one, because i can't figure out where the microswitch wire goes to, to unplug it from the harness and test the ends. I thought i could maybe pull the wire from the switch itself, but i couldn't get enough purchase to pull it without possibly damaging the wires.

i don't even have the tools (big enough torx bit) to open the rear housing over the tail light yet to see if the wires are all connected ok.

Thanks for the info though, i'll keep plugging away at it
 
#8 ·
resolved... both brake light switches were not being triggered, causing the forever on brake light.

the front one needed to be readjusted again (i had done it a couple of times, obviously incorrectly) and then at the same time had to manually push the rear switch, since that one is not lined up with the brake lever arm for some reason. i have a temporary fix right now of a nut and bolt through the arm to make contact with the switch.

thanks for the help
 
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