Many of you probably know this, but, if your door locks and power windows stop working, the cause is probably old electrolytic capacitors in the door modules.
I realized that, because of the age of the car, the problem might be related to the condition of the electrolytic caps.
So, checked out the rear door control modules, and sure enough, bad caps, which also took out some circuit traces. Replacing the caps, and repairing the traces, brought the door locks and windows, back online.
Did the same with the seat control modules on both front doors, which restored all seat function.
Did the same on the fault display module, which sometimes indicated a transmission malfunction. Sure enough, bad caps and circuit traces. Repairing it, stopped the malfunction indication and also fixed the cruise control.
Thought this might be helpful.

Just a quick addition, with a little trick soldering, most of those caps up to about 22 microfarad can usually be replaced with 0805 or 1210 ceramic (MLCC) types that are impervious to ripple and breakdown like 'lytic caps. Then a job well done won't ever need to be repeated.