HELP! 1992 Lumina A/C problem

I have a 1992 Chevy Lumina 3.1 V-6 that I cannot get the AC to work.... I can run a jumper wire off the AC relay under the hood to ground and the AC
will blow very nice cold air but in doing so the compressor will not cycle. I have had EVERYTHING under the dash and hood checked all relays, fuses, grounds, etc. and have even replaced the in dash control panel but it will still not work. Someone told me it could possibly be in the computer brain itself? Anyone have any suggestions? Thank you in advance.
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Check the clutch on the compressor.
Dave S(Texas)
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Low freon can also cause this.

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The A/C clutch has been checked out and R-12 freon is at proper level.....any other ideas?
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If the air is cold, the compressor has to be operating. When you say 'cycle', do you mean the clutch doesn't disengage? IOW, the compressor doesn't turn Off?
With the AC controls On (no jumper wire connected), check for voltage at the Low Pressure switch. If no voltage to that switch, then there is an electrical control problem. If voltage is present at the LP switch on one leg, but not on the other leg of the switch; either the switch is bad or the refrigerant is low. With voltage to one side of the LP switch, install a jumper to 'bridge' the switch......the clutch should engage(compressor On).
Are there any trouble codes in the computer?
Hope this helps.
Dave S(Texas)
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I'll take a stab at this. The '92 Lumina, I believe, is a "W" body. I had a '92 Olds Cutlass Supreme, also a "W" body. That car had the "V5" a/c compressor. The V stands for variable, as in variable displacement. That compressor clutch will not cycle once the a/c is turned on. It varies output with a movable wobble plate internally that moves as a function of inlet and outlet differential pressure. There was protection for the system with a system low pressure switch, I believe, that would open the clutch circuit to protect the compressor. You need a manual on the car to see if I am in fact right that the vehicle has the V5 compressor, along with a wiring schematic of the clutch circuit. Very helpful would be a graphic of underhood components to locate the low pressure switch so you could jumper the connector to see if the clutch stays engaged. If it's blowing a good cold, I doubt it's low enough on freon to close the low pressure switch and the switch could possibly be bad. Hope this helps.
Garrett Fulton
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gfulton wrote:

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