elusive electrical problem
This forum is great! I have found a lot of useful stuff here but nothing like a solution to my elusive electrical problem. Any help is appreciated.
My 93 Grand Cherokee has only partial electrical function. Windows work but AC, power door locks, interior lights, security system etc don't. The overhead console works (except for the distance to empty). The information center doesn't work.
The motor runs fine. All the fuses (inside and in the engine compartment) look good.
Before this we had a few broken wires in the front door hinges that we repaired whenever they broke. We hadn't yet gotten around to fixing the last break (driver's side - window lock wire broke so that only driver could open passenger windows) when my son pushed up on the rear passenger overhead light to turn it on. When he did, the lights went off and all the above-listed functions stopped. When we took down the overhead console, we discovered a broken plastic tab that apparently allowed the electrical contacts to touch the metal roof. "OK," i thought, "it must have blown a fuse." Nope, the fuse (20amp - instead of the 15 amp it was supposed to be) looked fine. We put in a new 15amp one anyway and still no help. My son fully repaired the wiring harnesses in the front door hinges (replacing wires - not the patch jobs we had done before) and the only improvement is that passengers can now open their windows.
Any ideas on cause or cure? I think that it may be a computer (controller?) problem but can find no info at all about such a device. Is there one? if so, where? Can it be repaired or replaced without resorting to a second mortgage? Any other advice?