I have a 1989 GMC Sierra c2500. When I press on the brake pedal, my brake lights do not come on. At first I thought the bulbs were burnt out, but when I took the bulb out and tested it with electricity it lit up just fine. My hazard lights use the same bulbs as the brake lights and my hazard lights work just fine. My turn signals work great too. But when I step on the brake pedal, I get no brake lights. I have replaced the brake switch under the dash. I have also replaced the neutral safety switch under the dash too, checked the fuses to make sure they were in good condition, and still nothing. What else could I be overlooking and or what else could be the problem?? Any help or advice would be greatly appreciated.

Thank you,
Brady James

 

try working your way back with a test light and see what if you can find a broken wire somewhere.

 

Look at the wiring under the rear bumper possibly from the hitch to hook up trailer lights, if you have one.

 

Also brake light switch wires run up to the turn signal switch and then back out.....also do you have power going into and out of the brake light switch?....also CHECK FUSES!!!!! it sounds stupid but you would be surprised...most trucks have a stop light fuse or relay in them....and a combination stop/turn fuse....check for these you may find an easy fix.

 

I agree w/ RoughNeck

 

Also the brake light switches on those trucks are adjustable. Make sure it is adjusted properly.

 

Thats right!!!!!! I forgot about that little bit of info.....been awhile since I owned an 80's chevy truck........also I have some wiring diagrams if you need help with those.

 

Thanks everyone for all your suggestions and help. I was unable to trace a broken wire, but what I was able to do to temporarily fix the problem was put a jumper wire in the brake light switch from orange to red. I used a volt meter to make sure the brake light switch was getting power and the reading was positive... so I'm not sure why or how it won't work by itself because it's a brand new brake light switch. But with the jumper wire in there my brake lights work perfect.

 

Good deal!

 

If you have the circuit boards in the tail light(behind the lense) it may have fryed easy fix really and mimimal cost