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A/C Will not come on

2850 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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If it's telling you that you are low on refrigerant, changes are it is.
How do you know that the system has enough refrigerant? Did you hook up a gauge set and check the high and low side pressures. If all you used was one of those cheap low side only gauges that come with a can of refrigerant, that is useless.

P.S. You didn't say, but I assume you know it must be checked at idle or slightly above (1500 RPM).
I think you have a misunderstanding of how the system works. The amount of "refrigerant" in the system has no affect on compressor cycle times. It WILL disable it if too low. Compressor cycling is controlled by the A/C refrigerant low temp sensor. It turns the clutch off at at temperature of 28 deg. Fahrenheit to prevent freeze up and on again at 50 Deg. to maintain the evaporator at a temperature between those two ranges. Obviously, cycle times will vary with ambient temperature.
I think you mean refrigerant, but in essence you are correct, he is low. That MIGHT play a small part in the cycling as the evaporator may not be able to maintain the appropriate temperatures if the refrigerant levels get too low.
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