I have a 2005 Deville DHS. I replaced a faulty rear passenger window regulator. I drove the car five miles and my radio and nav turned off, my dash lights went out then back on flashing tire monitor warning, service air bag, stability system etc. The radio would come back on for awhile then go back off. Not believing in coincidence, I unpluged the rear passenger door window module and everything went back to normal except of course the passenger window and door lock. The window module has three plugs, one with 4 wires, one with 12 and one with 24.
I can leave the 4 and 24 wire plugs in and it will still work fine. If I plug in the 12 wire plug all the weird things happen again. I tried different window module but no luck. I checked all the wires for chaffing and they all check out.

Anyone have any ideas?