Diagnosing A/C - Blowing Warm/Hot Air

[markaz]

'92 XLT - Just had the compressor replaced along with a new A/C hose as well. The system was completely charged. Air was bitterly cold for the first 24 hours and then cold to barely cool for the next 24 hours. Now what comes out of the panel is hot air. All the work done was warranty work at the shop I trust implicitly and was done 5 days ago. They don't know it doesn't blow cold and I'd like to try diagnosing what the problem is before I call them. Reason is we just became a one car family and I don't want to sit around their shop 2-3 hours. What's the shopping list of things to try in diagnosing what the problem might be?

 

[Number4]

Well, you need to hook up a manifold gauge set and check your pressures.

Harbor freight sells one for $49 on sale.

You can lookup r134a pressure charts on the net based on your ambient temperature. Make sure your pressures (low side high side) are good.

Also, do you hear the compressor kicking on? The front plate engaging and spinning then not.

I'd expect you'll find an empty system. Could be that the evaporator or condenser went bad after their repair, could be that they don't know what they are doing.

A leak would show up when they put a vacuum on it.

You need to find out if the system is empty or not. Just take it back to the shop.

 

[markaz]

"Could be that the evaporator or condenser went bad after their repair, could be that they don't know what they are doing." Well I took it back for the third time and the owner actually had the balls to get pissed off at me. I said I didn't want to be there any more than he wanted me there. His followup was somewhat telling...."You expect me to do warranty work all day long of the shop I bought". What could I say except 'Not my problem'.
I bought an A/C Pro R134a Refrigerant and loaded a very empty system first thing this morning (3:00am). Still worked great at 9:30am. At 12:30pm the vents were belching out scalding hot air. I live in Phoenix where it hit 119 degs today and limped home to make an appt with somebody who isn't stuck with warranty work.