EDub

I've searched around a bit, but I haven't come up with anything to solve my problem.

I have a 92 Pickup and the brake warning light has been coming on..but at half power as if there is a short somewhere. It seems to come on and go off at completely random times as well. I have checked the sensor in the brake master and the parking brake switch but the both seem to be functioning fine, the light will come on at full strength when the parking brake is on or the brake fluid is low. I'm really not sure where to go from here.

Anyone have any ideas?

abecedarian

it's possible either switch has corroded contacts. also, check your battery voltage with the engine running.

corax

try disconnecting th eparking brake switch and then the brake fluid level switch to see if the light goes out

EDub

14.23V just now. I unplugged the brake fluid reservoir sensor and went back to the cab and it was off. I'm unsure if thats the problem until the light comes back on again, then I'll try wiggling the wires at the brake master again. I did the parking brake switch already and it didn't turn the light off.

corax

Good job . . . I'd say it sounds like you found your problem - just leave it disconnected if that doesn't bother you (incentive to check fluids every week)

abecedarian

^+1
yep, the master cylinder fluid level switch is subject to corrosion due to its exposure to brake fluid, moisture in the air and dust.
If you can get in there, you can clean the contacts with electrical contact cleaner available at Radio Shack and other places.

and 14.23 VDC is an excellent battery voltage reading, by the way.

EDub

Thanks for the help guys, It happened again just now when I went out so I left it unplugged. I'll probably just fix or replace it when I have the time.

keithdphan

also disconnected plug at m/c

Jay351

Fill till its PAST the full line. Common problem, that will fix it (usually), that and a sticky sensor.

EDub

Alright I'll give that a shot too.