dumb brake question

[ecmo92]

Ok I noticed a busted electrical wire going into a plug on my rear drum and for the life of me I cant find out what it is. This is not the brake switch up on the frame, this in on the drum it self. Looking at a few pics that I could find I didnt even see this on other xs650s. Mines a 74 tx650. All I can think of is theres a brake lining idiot light on the guages and thats it. But thats just a guess. Im gonna wire the bike all over when I get done with the bratification of it, but still, I was wondering what it was?

 

[5twins]

Yes, it checks the lining thickness, or more correctly, keeps track of the cam rotation. When the linings wear thinner, the activating cam turns more to apply them. Once it turns what Yamaha considered too far, the switch triggers the light.

 

[ecmo92]

Thank you! That was driving me nuts.

 

[BZNrider]

Was this only on a few model years? I could swear I've never see this on my '81.

 

[weekendrider]

Only the early models.