My A/C was working for a while but its really warm now. The compressor turns on and off but I do not get anything for cold air. When it was working if i gave the car gas it would get warm and the air flow would shut down too ? Any ideas ?

 

Sounds like the system is low on refrigerant. And you need the valve that controls the vacuum to the vents, the exact name escapes me but a Volvo place knows what it is-cost little and is easy to fix.

 

Where is this valve ? Passenger area or in engine bay ?

 

Check freon levels first. and the valve is located with te car on front to ur left near the dryer I think is called is has switched on it.

 

In addition to what Bluewater1 did here, in your case, I would also replace the Heater Control Valve (which is in the engine compartment, on one of the heater hoses/lines). These valves are cheap: $ 15-18 shipped.

When you check the Vacuum Controller, check the vacuum lines for cracks. Check also the vacuum reservoir for cracks.

 

I'm guessing you have automatic climate control? ACC? If so, there is also a very good chance the controller is weak or bad. On my 760, I could not use the auto position. I had to put it about 85 degrees and when the temp got down to that, I would start easing it down a few degerees at a time. Eventually it would cool at the temp I wanted. Air flow diminishing is a vac issue. It's quite possible you have a number of issues going on simultaneously.