98 wont blow cold anymore

[LJRuddy]

Friend drives his SHO around for a living and tomorrow its gonna be well over 102 out...

Ever since he bought it, it blew the coldest air in any car i have ridden in... Until last night. Started to blow hot air and we had to cycle from AC to OFF a few times before it would blow cold again. Even then, the cold air would last for a minute or so.

We checked the compressor and when the AC is turned on, it wont even move. Radiator fans turn on, engine adjusts rpm as it should blower fans kick on. No compressor movement at all. All connections are good and there are no fuses blown that would associate themselves to the climate control system.

Could it need to be recharged? Compressor blew up instantly? Need reshiming all of a sudden?

If is needs recharged, why would it blow ice cold one minute, and loose all of its charge in seconds?

 

[NebraskaSHO]

Buy one of those refill cans with a gauge on it. Mine was a little low and now it's back to normal being ice cold.

Just an idea.

 

[LJRuddy]

And if it is low, how do i refill it? Ive never done any sort of work on an AC system before... Is there a link to a how to?

Also, what are the optimum levels of refrigerant? fill from the low side right? do i also check levels on the low side? What is the high side for then?

 

[NebraskaSHO]

Me either, I just went to AZ and bought one of the silver/blue cans that are supposed to refill your refrigerant. It had a gauge on it to check the pressure in the system.

I read the instructions and did as it told me. Hardest part was to get the quick connect fitting from the cans hose, to fit onto the fitting by the firewall. That was a PITA and I had to "improvise" with vice grips and water pump pliers.

Just had to keep the car running with MAX A/C on it's coldest setting while I tipped the can around to get all the stuff out.

 

[FoSHO99]

my car has been doing the same thing, but It will blow ice cold air then it hits the desired temp, then it never kicks back on... so I shut off the a/c for 10 secs and turn it back on and its ice cold again... sometimes I will drive for an hour and it never shuts off, then all of a sudden it will blow warm air....????? help please...??

 

[Silvapain]

Do the broomstick test to see if it needs to be shimmed. If that doesn't work, jumper the low pressure switch and see if it turns on. If it works when you jumper the low side, you probably need more R134a.

If you're going to buy a gauge, buy a decent one that reads both high and low side pressures. Harbor Freight has one for about $40.