I'm hoping maybe somebody can pin down what and where the problem is. I cracked my windshield. After getting it replaced, I experienced intermittent electrical problems: Door locks unlocked after starting. Dash/running lights flickering/vibrating rapidly on/off. I tried leaving the fob home and driving without it-no change. Disconnected battery/cleaned terminals/ charged-no change. Extensive web search gave no clues. Looking at the Haynes wiring diagram showed something called ETAC in the circuit. That let me find people with the same problem, stating the fuse for the dome light was blown. I checked the dome light fuse-yes, it's blown. Replaced the fuse-doors lock and lights work normally! Check all fuses-OK. Check all lights- Everything works EXCEPT the dome light. The puddle/door lights and the driver's courtesy lamp in the visor work. Alarm, locks, lights, wiper all function. I tried 2 new bulbs, and tested the ones in the lamp-all four are good.
So my assumption was that when they changed the windshield, they shorted the +12V lead from the fuse to the courtesy light, blowing the fuse and damaging the wire. HOWEVER, testing the connector with a DVM shows +12V on the hot wire. Connecting the grounded side of the lights to a known ground with a clip lead causes them to light. Neither of the wires for the - side of the light show ground with the DVM connected to +12V. I know the door switches are working, because the door/puddle lights work normally. I presume the ETAC is working because the door open indicator, wiper delay, and key fob work normally.
I tried pulling the visor and looking at the harness for the visor light, but it didn't tell me much. Pulling the dome light and trying to trace the harness didn't tell me much. It appears the wires head towards the "B" pillar, although I assumed the wires run through the driver's side "A" pillar from the fuse block/ETAC.
I'm flummoxed by the two ground wires being inoperative. Somebody shorting the +12V to ground with a prybar, damaging the wire and blowing the fuse, makes sense. Somebody managing to damage BOTH ground wires enough that they don't function, plus shorting the +12V to ground enough to blow the fuse, seems unlikely. Since the wires are hidden under the trim and headliner, I can't check them without pulling stuff apart.
I have tools, DVM, a parts car, and mechanical and electrical knowledge. I'm posting in the hope somebody can tell me exactly what is wrong or what happened, or just where the wires actually run. Other than that, I'm either going to make a ground for the courtesy lamp so I can turn it on/off, or pull stuff apart to see if I can find the problem or pull new wires.