AC troubles
 

Hello Everyone,

Any AC guys in the house?
I'm working on a '90 Seville that appears to have no , or restricted circulation in the AC system .
Is there a fixed orifice used in this AC system ? If so, where is it located ? If not, what am I looking for as the cause for the refrigerant not circulating ?

A little history. The car sits in storage for 6 months, then comes out of storage, and except for maybe having 200 miles put on it, it sits for 6 another months before going back into storage again. I know. Why bother?
The AC was converted years ago, and worked fine until last year, when it started working intermittently. Along with a few of the cars other systems, I feel the AC has crapped the bed from lack of use.

The information center says low refrigerant, but the system has a good charge. The system will not turn the compressor on, but when the compressor is made to run, both the high and low side lines begin to heat up, and the low side pressure stays at 60psi, while the high side jumps to 300+.:eek: If the compressor is turned off, and then back on again, the low side will drop to 20psi, and the high side is 250psi, and the line entering the evaporator will frost up. :cool:
Even though the line entering the evaporator is frosted, the air from the dash never gets past cool. :(
Then, after running a couple of minutes the pressure starts to rise again for no apparent reason, and the lines start to heat up as well. :confused:

My thought is a blocked orifice / expansion valve. Or... am I way off on this ?

As always, a big thank you for any advice.

hey, i know nothing about AC units but just looking at the symptoms and having had similar questions with other cars, i can say that if the system says LOW REFRIGERANT, it is low .. when AC units are converted, AC shops use a chart on the amount of recharge and for some reason, on GM cars, there seems to be a mis-calculation .. .. that is a long winded way of saying follow the car diagnostics ....

next, if the evaporator is frosted and NO cool air comes out of the vents, it sounds like the flaps that control air flow are not working or stuck ...

the other comment i will make is that if the car sat for a year without running the AC compressor, the system seals are probably compromised (shot) .. they depend on the refrigerant to lubricate them and keep them pliable.

between low refrig, non-working flaps, and leakage, any by itself or a combination of any, i can see a non-functioning system ...

as i said before, i know next to nothing and someone else may come along and provide more useful info ...


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