The furthest I can go back is a '96 model. I don't know if that's going to be the same but they show an Integrated Power Module. The Remote Keyless Entry Computer and all of the lock / unlock, and alarm system functions are powered off the interior lamps fuse. That fuse is a ten amp in the fuse box on the left side of the dash. It's in the third row of fuses. Check if it has voltage on both sides all the time. If there's no voltage on either side, there is a break in the wire going back to the battery.
Either the Remote Keyless Entry Module or the Integrated Power Module are involved in sending voltage to the various interior, trunk, and under-hood lights, and both are powered off that ten amp fuse. I find it highly unlikely one of those modules is defective, let alone two of them. As a point of interest, that seems like a lot to ask of a ten amp fuse to run two computers and all of those lights. I count four vanity lamps, three dome / map lamps, (only two with moon roof), a trunk lamp, two courtesy lamps, two instrument panel lamps, a glove box lamp, and an under-hood lamp. Even at only a half amp each, if all the lamps were turned on at once, it's likely that fuse will blow. That could easily happen when a computer is involved in what used to be a a simple, common sense circuit. Unlike mechanical switches that have to be manually turned on, many electronic switching circuits start out powered up, then have to be electronically turned off. Even if that takes a fraction of a second, you would think the engineers would design the circuit to not blow fuses, but they have proven over and over that they don't use common sense anymore. I don't see any other circuit or fuse involved in running the lights.
I really hope you find that fuse blown or missing voltage, otherwise we'll be looking at computer modules. Let me know what you find for voltages on that fuse.
Monday, January 9th, 2012 AT 9:02 AM