HVAC Control problem
 

K, this doesn't have anything to do with a mustang...it's in my daily driver (92 Cavalier)

When I turn on the Defroster (front) it turns on the AC compressor. WTF?

Anybody got any ideas?

That is normal.....

It never happened with my green 2 door.....it was a 94.

I dunno....I just hate it, it sucks the power right out of my car and lets face it.....it's only a Cav.....it needs all the help it can get.

If your car has a/c it is normal.If your other car had no refridgerant or had no a/c installed may be a reseans why you didnt hear it.In defog and mix position the a/c compressor cycles for a few reasons such as keeping the system operational,cooling the cabin, and to aid with the defoger if needed.

Actually, now that I think about it, you're right, the compressor ran out of refrigerant and it wouldn't kick in at all on my 94, Although I had a tank of R22 so I hooked up my gauges and got the compressor to work but it didn't last very long, would have worked if I had 134A but R22 seemed like a good idea at the time and that was all I had.

I guess I won't get too pissed off then....I just wish it wouldn't happen.