We haven't had to use the roof A/C's the past 6 weeks while in the Pacific NW, but this morning, with no warning, the roof air came on by itself, then shut off for a minute or so, then came on, shut off, etc. While looking at the analog control switch, I saw the two green lights illuminate for a few seconds, then go off, then the A/C blower came on, all this with the switch in the "off" position. I finally had to go the bedroom Breaker Box and turn off the breaker for the front A/C.
I just (4-5 months ago) replaced the top (roof) circuit board with a new one I bought from Gary Bouland. Could it possibly be the inside analog control switch? I do have another one of those, also courtesy of Gary. Tomorrow we cross over the Cascade Range (from west to east), so we'll be in warmer weather and will need to use the roof A/C's again (bummer). I hate to think that it might be the relay in the roof circuit board, as it was replaced so recently.
Any ideas?
I had one of the relays stick closed for the bedroom unit in my 93. You can actually remove the board, desolder the ac and heater relays and swap them. This is on the roof board.
First try pulling the wall control or replacing it if you have another, if not above post is next. Betting on the wall but I bet on Dewey.