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.
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
Are there any trouble codes in the computer?
Hope this helps.
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.
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