Front hand brake switch - failure

[Red]

I've been fiddlin with my '85 K100RS bike and noticed that my rear brake light light will come on, somewhat intermittently. Being a newbie with my bike, I did some internet research and have come to the conclusion  that I might try to clean my electrical connections (both ends) on the front brake handle switch. On this switch (cable) one end has a plunger that rests against the front brake handle. As I wiggle this front brake handle the back rear brake light flickers on and off. The running light is fine and stays on continuously. Suggestions on best approach to clean and retro the plunger end? I will pull my tank and trace my cable to the connection in the wiring. Suggestions on cleaning both the male and female portions of this electrical connection? Lastly, am I beating a dead horse and should I abandon this cleaning idea and just buy a new switch?     

[mystic red]

I don't think it's a connection but cleaning those and applying a little dielectric grease to them is always good. I rehabbed the switch on the front brake and it's worked perfectly ever since. Also did the high/low beam switch when it wouldn't go into high any more with the same result. They are a pretty tough design but they get dirty. You might shoot some WD 40 all thru it before disassembling. If I remember right, that's all I did on the brake switch. Fixing the front brake switch is easier than the headlight switch. Lots of little parts in there preloaded with springs! ;D

[Red]

Yes sir! I sure like to hear things like, fix with WD40! I'm on it! Thanks for the response.

[Red]

I took the front brake switch off the bike and cleaned up the connection under the tank. I took a look at the other end (it has a plunger for an end) and covered it with WD40 and worked in and out the plunger until it was well lubricated. Installed the cable switch and it worked for most of my ride this morning .... but the symptoms are back again. I think I have a need for a new switch. BMW dealer price is $33.00 dollars each. I'm contemplating ....  :-\

[frankenduck]

They get dirt in them and fail or the little spring inside breaks from use.

[Red]

I visited my BMW shop again this morning and ordered a new front brake switch. It cost $33.00 dollars and some change. Is it worth for me to hang onto this used switch and try to fix? I was looking at the plastic casing that the plunger resides in and it looks like I might be able to pry open the half's of the plastic casing with a razor marking knife I use for wood working ... I've been known to make my own very small springs to be used for old "wood hand drill chucks"...but I'm probably dreaming just a bit ... ??????

[mystic red]

Hell yea, tear it apart and then throw it away..... ;)

[mnb]

I sprayed mine with wd40 and worked the switch to get some inside the switch to clean it and it's been fine since.

Worked great on a stuck hazards light switch, too.

[frankenduck]

Hey, Curt: Welcome!

[Red]

Thank you all for your comments and direction. I have installed a new front brake switch (part # 61 31 1 459 569). I am happy to report that my back brake light is functioning properly again when I utilize my front brake handle. Being new to K bikes this was a learning experience for me and a fun exercise. Your forum is a very nice resource for me as I continue to work on my '85 K100RS. Thanks again.