tpotter1100

2003 Audi A4 1.8T Quattro
Hey guys!
I have been chasing down why my trunk only opens with a key. I have checked every fuse. the key fob, the door switch in the driver side, and the trunk switch by the license plate, will not activate at all. I bench tested the plunger and it works just fine.
i noticed there are some strange wiring in the back coming out of the rear tail lights. There are wires spliced for the license plate lights and also for a towing trailer light. And the craziest thing is that SOMETIMES the headlight switch will pop the trunk. And SOMETIMES it will not. I cant seem to “make “ it happen on command.
clearly something is not right. Anyone have wiring schematics? Or hownto test these switches? Like what pin or wire should show voltage, etc

turbo510

Did someone install a rear-view camera?

tpotter1100

no doesn’t look like it

AudiAllTheWay

Possibly the trunk wire harness has some damaged flex point wires and a PO tried wiring around it. I prefer to either replace the trunk wire harness or open it up and splice new wires from inside the trunk to inside the rear quarter.

Suggest to open up the trunk wire harness at the flex section and inspect for cracked jackets possibly causing random shorts aka weird things can happen.