car stalls when A/C is on

[gst_01]

when i start my car, the idle is fine. when it is idleing, it is fine. once i start to drive the car and pull to a stop, the idle get really weak (RPM is below 1k). now that it's hot, i tried turning on the A/C. while driving, the car seems really weak and picks up really slow. but when i pull to a stop, the idle get really, really rough and the RPM jumps below 1k and then the car would stall. none of my buddies have DSM's, they have hondas, toyotas and nissans. they say the fuel pump is the problem for the weak idle and the alternator is the problem for the A/C. along the same lines as the A/C, my head lights and all lights inside gets dim when i pull up to a stop as well. basically, whenever i don't have my foot on the gas, it seems like the car is going to stall. any help???

 

[Lordpaxin]

Have you by chance recently charged the air conditioning unit?
or swapped a belt.

once i added to my ac, and it had the exact same problems, it was over filled too much pressure in the compressor. a over tightened belt might have the same effect.

 

[CurtTSI]

Sounds to me like an ISC problem. Test the coil resistances in the ISC, when the engine is warm. The resistances between the two center pins and the pins on each side of it should be between 28 and 32 ohms. I suspect that you will find that one of the 4 readings is a very large value, open circuit.

 

[gst_01]

Have you by chance recently charged the air conditioning unit?
or swapped a belt.

once i added to my ac, and it had the exact same problems, it was over filled too much pressure in the compressor. a over tightened belt might have the same effect.

i think it might be the belts. i had all my belts replaced in december, but didn't use the ac until now. plus when i start the car up, the belts squeek. so i think that the belts might be too tight. now, which belt would it be. is it the one that connects to the alternator?

 

[92awddsm]

Sounds to me like an ISC problem. Test the coil resistances in the ISC, when the engine is warm. The resistances between the two center pins and the pins on each side of it should be between 28 and 32 ohms. I suspect that you will find that one of the 4 readings is a very large value, open circuit.

Exactly what he said^^^