Car stalling when A/C is on

[street591]

A friend of mines gt keeps stalling. So figuring it was the infamous stall problem the iac got replaced but it didn't fix the problem. Recently it was noticed that it only idles different or stalls when the air is on. I can only think of a few things it could possibly be. Any help on this one is appreciated!

[2001GTTT]

take it to advance or autozone and have the alternator checked, or maybe its some type of vacuum leak whent the a/c gets turned on....and you already replaced the IAC, so if its none of those, i dunno.

[Hawkeye]

Could the AC compressor be seized? Any belt slippage?

[street591]

No belt slip. Its only when the air is on and pulling to red lights the idle will drastically change or flat out stall

[Martin0660]

Not sure what year you are dealing with here ...

There are several things that happen with the AC on. The most significant is that the idle should increase becasue of the extra load. The EEC knows this is happening via a switch in the system. Depending on year, it could be different.

Also, the charging system can be in play becasue of the draw from the clutch but it's less likely if that is the only reported issue.

[383taman]

I would start by cleaning the throttle body.

[street591]

The car is a new edge.

I was thinking maf, frps, or tps but am doubting these with the discovery of the AC part.