1995 lumina 3.1 vin m

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1995 lumina 3.1 vin m

Post by chris50 »

condenser fan only works when relay is first plugged in, then seconds later turns off
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Re: 1995 lumina 3.1 vin m

Post by GM Tech »

If indeed this is a Olds "W" car sedan or perhaps a Chevy Lumina SUV "U-van" then the condenser fan "waits" until it sees 175psi pressure on the a/c high side outlet pipe to turn on the fan. Why run the fan if not needed? is the logic... Going down the road even on a hot day, your high side rarely hits 175psi. Only when you stop or idle for extended periods will it come on. Of course, if your a/c does not cool then you are probably low on refrigerant charge (most likely) and the fan is even less likely to be commanded on.

The fact that it comes on at all, gives me confidence it is working just fine and the ECM has full control.

Yes, there are other cars, and other a/c system designs, that the fan comes on immediately with a/c commanded, but not a "W" or "U" platform vehicle. Been asked this dozens of times back in the day.....
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