Turn and brake not working on rear drive side only

[bob850]

This is on a 1993 C1500 Suburban.

My driver side rear turn and brake light are not working, and the driver side turn signal (on the front only) blinks really fast. The marker (parking) light works fine though. The reverse light also works fine.

I replaced the rear driver side bulbs, still doesn't work. I also swapped the passenger rear lamp housing & circuit board into the driver side, and it did not work. I also swapped the driver housing/board into the passenger side, and it DID work. So I think the driver lamp housing & circuit board are fine.

Also, when the hazards are on, the driver side rear hazard lamp does not work, but the other three corners work fine, and at the correct speed.

I also put my meter on the vehicle connector that plugs into the rear driver tail lamp, and I am not getting a signal on the brake/turn wire when either brake or turn is activated. I observed the marker and reverse signal voltage just fine at that connector.

So that's what I know. Before I go digging through the wiring further, does anyone have advice as to what the culprit may be? The vehicle does have trailer wiring that was added aftermarket, but it has not been touched recently.

 

[1sickcrewcab]

Mine did almost the same thing. Drove me crazy i ripped out all the taillight wiring looking for a short. Dummy me didn't even check for good ground. And that was my problem. Ground was corroded. So check for good ground under rear of truck.

 

[bob850]

Last night I traced it back to a broken wire on the 4-pin weatherpack connector near the back of the frame rail. It looked like it was connected, but when I moved the connector around, the broken wire revealed itself.

It broke right where it enters the connector, so now I just need to figure out how to extract the weatherpack pin and recrimp, or just jumper around it.