Just got done with this one. There are two relays, one for locking and one for unlocking, located behind the center of the dashboard. They are triggered by either of two switches in the driver door lock mechanism, one a wraparound switch on the key lock cylinder, and one that operates by the locking stalk.

Pulling the fuse, # 8, will stop the doors from trying to lock/unlock, but it has an unpleasant side effect - it will cause the seat belt chime to sound continuously, even if the door is closed. You will also loose your dome light and the trunk and underhood lights.

The most likely causes of your problem is either a shorted wire in the wraparound switch or a stalk switch that is jammed or frozen. If you pull the driver door panel, you can unplug the switches (three prong plug, center bottom of the panel,under the moisture shield). You can test the operation of the relays and the actuators by jumping the black wire to each of the two color wires - can't remember the colors, but one should make the locks engage, and the other should make them unlock. If the test works consistently, channces are it's the switch. The wraparound switch is a PITA to get out and back in - before you remove it, pay close attention to the routing of the wires.

The combo stalk/wraparound switch is $65 + shipping at FCP Groton.