A/C whistles and hums, causes engine to stall when on

I am having the exact same problem with my 2001 Dodge Stratus SE 4 Cylinder 2.4L with 120,000 miles. I realize that I need a tuneup but this shouldn't affect the A/C only working when I put it on 4 then causing the stalling. Each A/C level went out one at a time. Now I'm on the last level and would like to get some idea of what this could be before taking it in to a shop.

Update: I personally replaced the blower resister, which was very easy to do and now my fan blows on all speeds. However, I continue to have the same problems with whistling and humming.

Nsyork112, sounds like you have the same problem with your car. The blower resistor is easy to install, took me only a few minutes. All you do is remove the carpet underneath the glove compartment and replace the chip. Only 2 screws. You can purchase one on ebay really cheap, or go to the dealer for a bit more. It's not worth paying someone over $100 to do something yourself that takes no time at all!

Thank You so much Nicolesbabes. I will definately purchase and do it myself. You just instantly saved me money. Does your car still stall when you turn your a/c on at all. I'm having to turn the a/c off until I start accelerating really good then I must turn it off at stop lights or when slowing down or it will stall when I take off again. Everyone says it's because of a tuneup. Does your car do the same? Thanks in advance.

Glad to help. Yep, my car still does the same, and I guess I haven't brought my car in for a tuneup in awhile. So perhaps that's what I need as well. Although, I've been doing a bit of research and there is the possibility that it is the A/C compressor that is causing the problem, as I have read when they are starting to go out, they sometimes don't spin with the belt as they are suppose to (at the same speed as the belt is moving). Thus, it sometimes causes the stall, as the A/C compressor slows the belt speed down a bit, in turn affecting engine power. I'm not completely sure on this however, but it will probably be something I'll put off until next summer since this summer is almost over here in northern Minnesota!