I had the same problem with my 944t. The ac would not come on at all. No compressor, no aux electric fan, nothing. It turned out that there was a bad solder joint in the ac controller head. My mechanic reflowed the solder at the bad connection and voila the ac works like a charm.

A new ac control board would have cost around $500.00 plus oem. I think there are others on this board who have had the same problem and will be able to tell you where the solder joint is to try it out. The aux electric fan should automatically turn on when you turn the ac on. If it doesn't I'm pretty sure you have the same problem. The relay for my cooling fan was/is fine. The 700/900 faq's will tell you where to find the relays, but since you have the same symptoms I had, I'm thinking it's the ac controller head. I hope this points you in the right direction.

Best of luck,



Mike

1993 944t 109K miles