ac compressor wont shut off

yellow95 · Post by **yellow95** » 07 Sep 2017, 09:15

Worked fine up until yesterday morning. I turn the ac off and it still ran. removed the relay still ran, unplugged low pressure switch. Still ran. Only stopped when I removed the fuse. Any clue as to what to check?

Gary

Post by **scot850** » 07 Sep 2017, 11:20

Are you sure it was the AC compressor? Does it no need the engine running to drive the clutch to drive the compressor? Are you sure it was not the engine cooling fan running as it is supposed to do to cool the under hood temperature? That can run for several minutes after switching off.

Neil.

Post by **wizechatmgr** » 07 Sep 2017, 22:23

If you removed the relay then removing the fuse shouldn't matter.

If I were the betting type, I'd bet the clearances in the clutch are too close or it was slipping, heated up and then grabbed...

Post by **abscate** » 08 Sep 2017, 19:40

Are we discussing the fan or the compressor?

Post by **wizechatmgr** » 08 Sep 2017, 21:18

If the issue is a fan -- are we talking about the blower in the passenger's compartment or the fans on the radiator. If the latter, it may run for a while if the coolant is hot enough. Double so on a hot day with stop and go traffic.

Post by **scot850** » 08 Sep 2017, 22:47

That is what I asked at the beginning, as I can't understand how the AC compressor can run on if the engine is stopped, as the serpentine belt needs to run for it to turn the compressor. Hence (maybe wrongly) the supposition that it is not the AC compressor but actually the engine cooling fan doing it's thing to reduce under hood temperatures to lessen the chances of overheating under the hood. If that is the case and it is the engine fan, it is meant to do that.

Neil.

Post by **jimmy57** » 09 Sep 2017, 07:55

I hate it when alien craft levitate posters and returns them to that other planet right in the middle of a posted issue.

Post by **oragex** » 09 Sep 2017, 11:03

From his description, it's really the a/c compressor that keeps running even with the switch turned off. That's one resilient compressor, could it be the clutch plate got stuck on the pulley for some reason?

jimmy57 I can feel ya, small consolation, they are driving Volvo on other planets

Post by **mrbrian200** » 09 Sep 2017, 11:45

wizechatmgr wrote: 07 Sep 2017, 22:23 If you removed the relay then removing the fuse shouldn't matter.

Unless there were a short in the wiring. With the relay pulled already if pulling he fuse disengages the compressor clutch that would mean the short would have to be between two specific wires - the power feed wire coming from the fuse shorted to the relay output that goes to the compressor right around or inside electrical distribution box.

Post by **wizechatmgr** » 09 Sep 2017, 17:16

I'd be willing to bet he fixed it.