Brake Light Stays On

[axlray13]

I have a 82 R100 and the brake light stays on all the time. It's the rear switch and it seems really hard to get to. The foot lever doesn't appear to hit the switch button, it's off to the side. The bike is in great shape and nothing is loose to explain why they don't make contact. Has something fallen off?
Ray

[shire2000]

Sounds like either the switch is faulty or the wires have somehow shorted across each other. Usually it is the switch, which can be a real PITA to swap out. they are not all that expensive, but you need really small hands and long thin fingers to get it bolted back in place.

[axlray13]

I can manually push the button on the rear switch and the light goes off (or on). It's like the pedal lever and the switch button doesn't line up. It's like an 1/8" off. Everything is clean and tight, no wiggling at all. Is there a cap that goes on the end of the switch button to make it bigger, because it's only, maybe an 1/8" diameter at most.
Ray

[tghsmith]

there should be an adjusting bolt/locknut that comes in contact with the switch pin, I set mine up so I can flic on the brake light without braking, can't remember if loosening the switch screws will give any side to side movement..

[sumran]

Also check to be sure the return spring on the pedal is operating properly. If the back hook is broken or not properly attached gravity keeps the brake light on.

[GlobalRider]

I have a 82 R100 and the brake light stays on all the time.

If the brake switch plunger is seized in the "in" position, then the brake lights will be "on" all the time.

Your switch is different from the one on my R100 GS, but the micro-switch on that model tends to stick "on" as well after time.

Take some WD-40 and spray the switch plunger and activate the plunger with the tip of a long thin flat-bladed screwdriver. See if that frees it up.

It could also be that the switch is defective/broken and that the internal spring has failed.

[lostboy]

The adjuster bolt on your bike should have an off-white cap on it, part number 23 41 7 650 149. This was to correct for misalignment.

[axlray13]

Thanks guys for all the input. I think the missing cap is the culprit. I'll let you know the results.
Ray

[RandyB]

http://bmwmotorcycletech.info/brakeswitches.htm Not specifically for your 82, but it's hard to tell what you'll find.

CRC 2-26 spray is a better friend than WD 40.

[lostboy]

I gave the wrong part number. The correct number is: 35211244520.

[axlray13]

Well, what I did was to take off the brake lever and add a washer/spacer to move the pedal sideways so it makes contact. Works for now, but I shouldn't have to modify it like that.
I'm going to show my bmw dealer the recall posting about the brake switch that Randyb sent me. Maybe it's the same part # that lostboy sent me, but I couldn't find that part on Max bmw fiche.

Thanks, I'll let you know the outcome.
Ray