Well, the Plymouth dealer tried repairing the locks (See my post above). They ran diagnostics. I'm not sure what turned up, but they did replace some switch in the driver's side door. They supposedly turned off some computer mechanism that would disable them, and tried a sequence of moves with the ignition switch that would disable them. Zippo. Still the interior door locks turn off and on randomly.
Today they were firing away intermittently as I drove around town. When I got back, and then went out about 2 hours later, they were pretty calm.
Thanks to our local small town library I can looks at Chilton manuals for the electrical diagrams for the lock components. Junction block pages, left/right door arm/disarm switch, and others. Probably 25 diagrams.
As from above, this all got started with rodents getting into the engine compartment. They fixed all other electrical damage successfully.
It doesn't look to me working one's way through the 25 devices is going to be fruitful. Possibly they can check all easily with their diagnostic devices.
It seems more likely damage was done to a wire in the harness. I don't see a diagram for one in the many categories in the Chilton DB.
Any comments on this?
I just found a pic of the engine compartment and what I believe is the harness. It is wrapped in black. I think another examination in the day time might be useful.