Buick Repair Questions? Ask a Mechanic for Answers ASAP
Hello, my name is Bobby. Thanks for the question. You are on the right path that it sounds like a circuit issue. Most of the time this is caused by a problem with the wiring that goes into the rear door breaking or wearing through. The wires needs to be checked by opening the wire loom and checking them. If they are fine then we will need to check the grounds for the system. Did you plan on doing this yourself?
That is exactly where you more than likely have the issue. The panel does pop off but it has a couple of screws also. I can see if I have a diagram of it. You should be able to see a rubber gromett that the wites go through leaving the body and entering the door.
I am sorry for the delay. I do not seem to have any diagrams of the rear lift gate trim panel on your vehicle. Let me check a little further.