Hello!
I'm writing this cuz I just bought a used eclispe in Febuary...and come June, I notice whenever I turn on the airconditioner (and the heater in the past) that, when I'm at a stoplight my 2003 eclipse starts chugging. There's a little over 50,000 miles on it so I wanted to know if it's an airconditioning issue or spark plugs. Booo! What is really wrong with it? And if anyone has an idea...how much do you think it will cost?
I feel stupid cuz it's getting hot but I suck it up and keep the windows down but I really want to fix the problem. I hope that it's not an engine issue....
Could someone please help so that I can feel more confident getting repairs and not be shocked?

 

Sounds like your clutch/clutch bearings or compressor might be bad or bound up. Certain heat setting also engage the a/c compressor (any defrost setting).

Running the compressor will also take away 10-20 horsepower from the engine and that might be enough to exacerbate another problem not related to the a/c system like a fouled plug etc.

Good luck .. hope you find it and it's cheap to fix.