I checked out online Mazda parts and found this...
I assume that's the fan switch. It's kind of a crappy drawing.
I think it was drawn by a 7 year old with a crayon. Lol
I also found 4 different choices for the HVAC control unit ranging from $250-$380.
I assume my car has the $250 unit, because my car was built in September 2001 and my HVAC unit is crap. Lol
I don't know what version is the improved version that is more reliable but you may be able to find that information on the AC threads.
You could also look up the part numbers for the MPV to compare.
If it has one of the same part numbers then your probably go to go with a used MPV control unit.
I forget what year of MPV is compatible with our car and what parts are interchangeable. (wiper & signal stalks I think?)
Our HVAC control unit is a bit tricky because if you have your air input set to recirculate, and you switch your selector to defrost, it automatically switches the input air to fresh and turns on the AC.
I kinda forget, I did the mod to bypass the AC and recirculate a long time ago.
That could have something to do with compatibility issues with other vehicles, but I'm almost positive that any HVAC control unit from any P5 will work with any P5.