Still trying to resolve air conditioner problem in '94 Civic EX Coupe. Problem began with cool air blowing when cruising along, but hot air blowing when stopped. Now I have nothing but hot air blowing. A technician said it needed freon but when he tried to put it in yesterday, it wouldn't go. He doesn't think it is the compressor but probably a clogged vacuum. He's to look at it again tomorrow. But today, I took it to another shop and the guy told me it was the compressor because he said something was not clicking on and off. Who am I to believe? Should I let the first person look at it again or believe the one who said it is the compressor? Need advice ASAP !!!

 

I have the same problem: cold a/c when engine speed is above 4K rpm (i.e. cruising) and hot/ambient air when idling. In my case it is the compressor. However, you said that you don't hear something clicking on/off. That is the a/c relay that actuates the clutch on the compressor. This basically turns the a/c on. If the line pressure in the a/c system is low, there is a low pressure switch that disables the a/c system to prevent damage. If you don't hear the clutch turn on and off, you are probably low on refrigerant. If you hear the clutch and rev the motor up and get cool a/c, it is likely the compressor.