On my 2004 Blzr 2 door with no brake lights, but good tail lights, I have tried the following fixes: 1./ brake light switch on pedal, 2./ Cleaning grounds and 3./ replacing the M.F. switch aka the turn signal sw. Still no brake lights. My friend who had an early 1st gen. keeps telling me to check the circuit boards in the tail/brake light assembly. I keep saying the 2003 has no circuit boards, just the traditional sockets and bulbs. Is that correct? When did GM drop the circuit boards? I have looked at the LMC catalog and see no Cir. boards offered for the 2003.

 

just checked alldata... no service bulletins for brake lights inop. is the car equipped with an alarm or did the PO have one installed? that could affect the lights... you might end up having to trace every wire to find out where the issue is.

 

emailed you some wiring diagrams from alldata (assuming the email in your name is your email address). hope they help

 

You are correct, it's just simple wires and bulbs back there.

 

No circuit boards in 2nd gen S&T. Nothing about checking fuses in both fuse panels. Do they all test good on both terminals on top of each fuse? Check circuits at the hazard switch. Both stop lamp circuits go through it.

 

I misspoke in the first line of my post. It is a 2003, not a 2004! I did check the fuses with a DVOM and found all but two were good. Replaced those and no diff. I have no owner's manual and no FSM. I try to read the inside of the fuse panel cover and they all in GMspeak and hard to relate to brake lights. Desert storm, I did get your two wiring diagrams and they give the fuse panel 'names' when you trace the wires back to the panels. So once I do that, I can make a list of fuses that are related to brake light operation. I will recheck those. Thanks for all the help. Jim

 

behind the back bumper you will see the wiring harness
Especially if it has a trailer connector check for wiring splices