TDavanzo

iTrader: (3)

Ok this one confuses the hell out of me. My air conditioning work, my heat works through the upper vent and through the floor. When I switch to the defrost/floor or defrost only setting I hear a squeaking sound and the engine strains to run and drops to 500 rpms and will eventually stall. I thought vacuum but it doesn't explain the sounds I was hearing.

Any thoughts would be appreciated I don't even know where to start on this one.

It's a 1996 LT1 Trans Am

Formula413

iTrader: (1)

Using either defroster setting will turn the AC compressor on, so the squeek could be the compressor pulley. You might also have a seized AC compressor, that might cause enough drag to stall the engine. Try taking the serpentine belt off and spinning the AC pulley to see if it squeeks.

Luder[PAK9]

All true, but he said he has no problems running the A/C by itself.

Formula413

iTrader: (1)

Hmmm...my money is still on compressor and/or pulley issues.

TDavanzo

iTrader: (3)

I'll take a look at those when I'm back home this weekend I'm just curious as to why the air conditioning still works though if that's the case. Either way that's where I'll start to look. It just started happening suddenly though, literally it worked on the way to work and on the way home it worked halfway and I got stuck in traffic and that was it.

TDavanzo

iTrader: (3)

Started the car the next morning and it worked fine, it's been two days and I've tested the defrost numerous times and it works fine. I can only imagine that this is going to become a re-emerging problem in the future but for now it's fixed.