# AC Compressor Not Turning On.



## Rockhead (Jul 10, 2014)

My ac compressor is not kicking on. I checked the fuses and they all look OK. I looked at the relay and it looks fine too, but then again you really can't inspect a relay. A side note I just upgraded the headlights, they were plug and play so I don't think this was the cause more just coincidence in timing.

Has anyone had this issue.

Thanks!


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## Tomko (Jun 1, 2013)

Vehicle model year and mileage, please.


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## obermd (Mar 3, 2012)

Could be a refrigerant leak. It the pressures are off the BCM won't start the compressor to protect it.


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## ChevyGuy (Dec 13, 2014)

obermd said:


> Could be a refrigerant leak. It the pressures are off the BCM won't start the compressor to protect it.


This. However, there is a relay under the hood in the fuse box, so maybe the headlight modification isn't just a coincidence.

I'd have the car checked for codes. Just because the light doesn't come on doesn't mean there isn't any.


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## Rockhead (Jul 10, 2014)

The car is a 2011 LS with 66,000 miles. Also, I forgot to add, the in-car thermometer started acting weird and at first was displaying a wildly wrong temperature like -30 when it was around 85 yesterday and then wouldn't display anything after I turned the off and then restarted the car.

I'd be pretty shocked if it was low on refrigerant, the car blew ice cold on Saturday just before I installed the headlights.

Thanks


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## Tomko (Jun 1, 2013)

Well, it definetly sounds electrical. 

Why not reinstall the factory parts and see what happens?


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## Rockhead (Jul 10, 2014)

Yeah I guess I could at least disconnect the headlights and plug in the old headlights and work my way down the line. I would really like to avoid having to pull the bumper cover off of the car again, but then again I really like my Ac more than the new headlights!

Thanks for the advice.


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## obermd (Mar 3, 2012)

Rockhead said:


> The car is a 2011 LS with 66,000 miles. Also, I forgot to add, the in-car thermometer started acting weird and at first was displaying a wildly wrong temperature like -30 when it was around 85 yesterday and then wouldn't display anything after I turned the off and then restarted the car.
> 
> I'd be pretty shocked if it was low on refrigerant, the car blew ice cold on Saturday just before I installed the headlights.
> 
> Thanks


I'm assuming you're referring to the outside temperature reading. If the BCM is receiving really cold external temperature readings it won't start the compressor, again to protect the compressor. Check the wiring to the thermometer in the lower left (as sitting in the car) fog lamp bezel. I bet it's loose.


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## Rockhead (Jul 10, 2014)

obermd said:


> I'm assuming you're referring to the outside temperature reading. If the BCM is receiving really cold external temperature readings it won't start the compressor, again to protect the compressor. Check the wiring to the thermometer in the lower left (as sitting in the car) fog lamp bezel. I bet it's loose.


100% right, the harness on the outside thermometer was loose! AC works just fine now.


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