taillight issues

[quacklxgic]

96 4dr 2wd tahoe. both taillight running lights work with no issues, neither reverse light works, the right blinker and brake light doesnt work. sometimes when driving the right will go out entirely. ive replaced the control boards, bulbs, and fuses with nothing changing. attached is an image of the right taillight while the running lights are on, only time any bulb lights up on it. any help is much appreciated

 

[east302]

I’d start with the reverse since it’s simpler and odds are that if you fix it you’ll fix the others. Look for connector C409 (two possible locations below) and check for voltage at the light green wire’s pin when in reverse. The engine doesn’t have to be started for the reverse lights to illuminate.

If you have 12V, then the problem is between it and the lights. Note that the trailer wiring is spliced into the circuit in this area. Do you have the factory trailer harness or is it a homemade job (or both)?

 

[Eman85]

World's worst taillight design! Do you have a test light? Get a good ground, might have to run a wire from the battery back to your test light. Start probing to see if you're getting power. If you have power then hook the test light clip to power and check for grounds.