Been thru many things so far. New bulbs, new fuses, new circuit plates. Pulled bulbs slightly out to see if the socket was an issue.
Was told to replace stop light switch at the brake pedal. Is there a specific way to do this? I disconnected my battery ground. Removed the wire harness, removed the spring retainer. Lined it up with the new one, put the retainer clip back on, connected the wire harness. Connected the battery and still no brake lights.
My cruise control does not work. My primary breaks lights does not work. My third brake light works, running lights work, blinkers work and my hazard lights work.
Any thoughts to this? The stop light switch seems fairly simple but did not have instructions. There was only one way to put it on. I could not pull on the pushrod to line it up with my brake pedal all the way down or all the way up. Would this make a difference?
I also tried another idea I found by google search. I disconnected the battery, disconnected the plug. Plugged it back in, connected the battery. Then I turned the key on to unlock the steering wheel, put on my emergency brake, shifted to neutral and started the truck. Still nothing for primary brake lights.
Thank you in advance for any thoughts and suggestions.

 

I had a 2003 Trailblazer and there was a recall on the tail lights. The bulbs just kept burning out. Both socket assemblies at the taillights were replaced. The problem got somewhat better but still continued. Check at the wiring at the taillight assembly to see if you are getting voltage when the brake pedal is pushed. If not check at the brake switch to see if voltage is turned on when the pedal is pushed.

 

Tested wires to the circuit board. They test fine so I do have full voltage. The mechanic said there is nothing low or fluctuates. I did wire my trailer lights and ran them up to my tail light assembly. I put a bulb to drop in the lens so I at least have lights. Its not bright enough tho. It did work as I pushed the brake pedal down and did the turn signals.
I took it all apart again to start over. When I removed the trailer lights my brake lights started working. But its not as bright as it should be. What I believe is happening now .... I push the brake pedal and my running lights come on. With my running lights on there is no distinguished brightness.
Not sure if its related to this. Now that my lights come on when I hit my brake pedal, my ac and heater will bog down my truck and it wont idle. It kills over. If I don't run my ac or heat then it runs fine. It just started that.
So maybe I have more of an electrical issue than expected.
Since there was a change, ever so slightly in the right direction, I went back to the parts store and tried a new circuit board. It did the same thing. Lights off, push brake and running lights come on. Lights on, push brake and nothing changes on primary brake lights. The third brake light keeps working properly.