Hi, I di search, got some good info, but need more...here goes.
I bought this 91 pickup a month ago
and last week the turn signal would come on when I braked.
I've replaced bulbs, stop switch etc. with no luck. For a few days my turn signal would come on while braking. I looked at my trailer harness first and it looked pretty sad. I snipped it off, although it practically fell off, and the turn signal behaved normally again, but now the stop lights don't come on. Everything else is fine, signals, flashers, tail lights, backup lights are all okay. Using a multimeter, I found there is no 12v at the brake light switch harness (the one the switch clicks into.) I checked all the fuses I could find, and did not find any blown fuses! Are there secret fuse locations somewhere, hehehe? I was going to try to steal the 12v from the fuse box, but would rather find the problem.

Thanks a lot

 

Okay, I think the problem is somewhere between the brake light switch and the fusebox on the kickpanel. I should be getting 12V at the GW wire of the stop switch. No power is coming out of the stop switch, maybe I'll just put new fuses in to rule that out...still would love to get some help/ideas..

Thanks

 

You should be able to check the fuse with a test light, no?

I would guess the problem is probably with the wiring in the rear because of the trailer harness. Especially if it was simply crimped together by someone in a hurry to go fishing or something.

But if you think it is in the switch, try jumping the switch and see if the brake light lights up. If not, then the problem may be somewhere else.