My sister is having trouble with the a/c on her 01 Mazda MPV. It works intermittently. When she takes it to the dealer, naturally it starts working again, and the service manager says there is nothing they can do to diagnose it when it's working - which I understand. They say there's no tsb on this matter. I explained to her that intermittent problems are the most difficult, if not impossible, to diagnose for any mechanic.

I'm posting here to see if anybody has experience with this problem, or if they can take a good stab at what the problem may be.

Right off the bat, I'm thinking there may be a bad relay or the belt is slipping -- if Mazda has a cutout feature for belt slippage (I don't know).

 

There are no TSB's or common faults that I am aware of Kestas. Question back to you. When the A/C quits and is only blowing warm air, if that is what your sister is experiencing, check and see if one or both of the cooling fans at the radiator are running. That should help to narrow things down a little bit.