My 1997 Lumina 3.1, airconditioner quit working I recharged it and the compressor ran and i had cold air for about an hour. Then the compressor stopped again. What could be the cause and how can i fix it?

 

I would start by replacing the pressure switch.

You did take a pressure reading before and during recharge, right? Overcharging can damage the system.

 

I used a recharge canister with a pressure gauge on it and stopped rechaeging when the meter registered in the green or full mark.


Where is the pressure switch?

 

Remove some of the freon, in air conditioning less is more, see if removing some helps free it up. If you are inside the car when you hit you're ac switch you should see the rpm change or hear a sound (drag) on the engine. If you have an extra pair of hands go over to where the compressor is and listen to see if the clutch engages,, you can usually see it, the outside of the gear or belt pulley will move ONLY when the ac is turned on, if this happens, than at the very least you're compressor is engaging. too much freon at the wrong temperature can sometimes work for a while then stop, then if you are lucky like me it has a relief valve and will backfire spitting green stuff out, I was at auto zone and mine backfired and the guy said I got too much freon, I let some loose( Dont let epa see ya) and then much better. autozone has the cans with green oil to see where leaks are, and a guage that reads pressure and temp. or rather what the pressure should be at that temp. anyways it will most likely improve if you let some out. good luck, let me know if it works for ya

 

Of course the most obvious reason would be a pretty healthy leak somewhere in the system.

 

I agree with there being a leak, since you had to add to the system to get it to blow cold. There is dye you can put in the system. Let it run through the system and when it begins to blow warm again, use a UV lamp and search for the leak. Could be a line, fitting, bad o-ring, condensor, compressor clutch seal, or the evaporator core (unlikely on this model, they last quite a while).