SC3001995

I have begun to have intermittent electric door lock issues on my '95 SC300, 206K miles, in Seattle. Usually the door locks work normally. When they occasionally do not, the symptoms include:

• Driving down the road, the system will repeatedly lock the doors, whether they are already locked or not. Hearing the sound over and over is annoying.
• When stopped, triggering the unlock function from the driver's arm rest switch will not work. The lock function still works from that switch most of the time, but not always.
• Unlocking the driver's door with the key will sometimes set off the alarm. Relocating the driver's or passenger's door will turn off the alarm. Unlocking the second time will not reactivate the alarm. This has only happened first thing in the morning on a couple rather cold days, well below freezing.
• The problem seems to go away in weather warmer than ~ 40 degrees F, though not sure about that in this winter weather.

I have pried off the switch panel from the driver's arm rest and the connector and wiring seem to be in perfect condition. I unplugged and re-plugged the connector with no observed different results.

Anyone have any ideas how to fix this? Thanks.