Right Rear Stop/Turn signal out

clf2427 · July 30, 2014

I've been told there is some type of junction box around the spare tire area where all the harnesses that run the taillight and license plate light etc..I have a short somewhere as well...I just can't find this junction box..all fuses are good

bbeshoner · July 30, 2014

I traced the wire harness from the taillight to the front and there appeared to be a junction behind the spare tire to the drivers side of middle but it seemed to just be wires branching out of the harness into a box and the harness continued to the passengers side rear tail lamp. I found my short just over the right drivers side wheel well where the wire harness comes out of the firewall to the right of the brake booster. The wires that go directly into the underside of fusebox (UBEC) were resting on a bracket that may be holding the fusebox to the wheel well. I could insert a couple of fingers between the wires and the bracket and the signal went from fast blink to regular speed and the stop lamp worked. So I just put a small piece of foam there and all is good now.

studly · February 5, 2019

Thank you, bbeshoner! You helped me solve a years-old problem with my 2008 Chevy Suburban.

It has had this rear left-turn signal problem since way back. I've had it in the shop four times at a cost well in excess of $1000. They replaced the BCM twice and the fuse box twice only to have the same problem reappear.

When it failed most recently, I started looking for the problem you describe. I found that the problem centered around a wiring harness behind the under-hood fusebox (toward the driver compartment). When I pushed down on the harness, the turn signal stopped working. When I lifted up on the harness, the turn signal started working.

I felt under the harness and detected a sharp metal corner poking into the harness.

It is a difficult to access area. My solution was to wrap that area of the harness in leather and fasten it on with tie-wraps. Now, the metal corner cannot invade the harness.

Now, my turn signal works all the time. I can press down or lift on the harness and it continues to work.