Two problems (actually several others, but these two most annoying and mysteerious): (1) Right front passenger door does not lock when electric door lock switch is activated. Must manually lock this door. HOWEVER, sometimes the door will lock “randomly” for unknown reasons, when the electric door switch is activated by human or - by “ghosts” (self-initiated). (2) All door locks cycle on and off in rapid succession - like a demon has possessed the car, making the doors lock all together in unison, repeatedly, over and over, at a rapid rate – for unknown reasons (!) – seems to happen when the sun beats down on the car and/or after rain has fallen, but this is just a guess – the door locks have done this cycling on/off by themselves when we’ve been in the parking lot of a department store, too, seemingly unrelated to the weather! A local mechanic who’s claimed to be good at “tricky electrical problems” can’t solve the problem for us. HELP PLEASE ! can someone exorcise the door lock demon?!
The first two things I would check are the master control switches on the drivers door and the body control module.
When/If you obtain a solution to these problems, I’d be grateful if you’d post back with any details on where the problem was found and how it was solved. I have the same car, same year, with two mysterious electrical quirks, though less severe than yours. Thanks for anything you can share.
I would also suggest checking the wire bundle that runs into each door, near one of the hinges.
This bundle of wires is enclosed in a rubber boot.
If you open that boot (very carefully!!!), you will very likely find one or more wires whose insulation has cracked as a result of 16 years of flexing. In addtion to cracked insulation, you may even find that some–or all–of the strands of the metal conductor have broken.
After at least 16 years of use, any electrical/electronic component involved with the functioning of the door locks is suspect, but you shouldn’t forget about the wiring.
+1 to VDC’s post.