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A/C Will not come on

2847 Views 6 Replies 4 Participants Last post by  mhamilton
I have a 1992 Seville 4.9 litre. When I turn on the Auto A/C controls the message board reads very low refrigerant compressor turned off. I have checked the low side of A/C and the gauge reads that it is full to the correct level to operate the compressor. A/c always worked fine. I had changed the clutch and everything was fine.A/C system was never opened. I drove the car to AZ and during the trip I had the same message as above. I turned off the a/c and let the car sit. I had gone back out to check the a/c again and it worked fine. It seems after an extended period of time the A/C will then display the low refrigerant message and turn off the compressor. Now the A/c will not turn on at all anymore. there are no leaks to found as it is full of freon. This vehicle has been converted to r134 by a professionel shop.All other functions of climate control work fine. Any help or suggestions greatly apprerciated. :bonkers:
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first clear the codes - either by on board diagnostic or removing negative battery cable for a short while.

then start the car and hook up the gauge and then turn the ac system on when it should try to kick on before it realizes it does not have enough coolant. At that point the gauge will show you that it is in fact low on coolant. Simply get the amount needed (should be in back of vehicle manual) of r13a coolant and gauge with trigger. follow the instructions and what you will notice is that the compressor will turn on and the gauge read low - then it will turn off because of lack of coolant and will read high (pressure) then back and forth back and forth - the whole time this is happening you should be adding coolant as per the instructions on the bottle. After awhile and it will take longer than you would think the compressor will finally kick on and stay on for longer and longer periods of time as more and more r13a can get into the system. - keep going until you reach the correct pressure.
If you want to find out if you have a leak get a can of the r13a that has the chemical which will glow under black light and leave the ac on for awhile and shine a UV light to try and find the leak.

hope this helps
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you are correct. I do not know completely how the system works - I just know that when mine said low refrigerant it was cycling on and off quickly when I reset the codes to add more. I hooked up a can of coolant with a trigger gauge and it was cycling on and off rather quickly - I would say 5 seconds on then off until the coolant level rose (took awhile because I would only add coolant while it cycled on at which point it would stay on for a longer period of time and off for a longer period of time until I reached the correct pressure. I apologize for explaining it incorrectly however, When I added coolant that is how it went.
So I guess in essence all I was really saying was that more than likely he is low on coolant.
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