# AC Compressor Clutch Not Engaging



## jblackburn (Apr 14, 2012)

Is the outside temp on the radio screen displaying correctly?

The A/C may also not engage if the car's upper and lower coolant temperature sensors don't agree. Is the engine fan screaming when the car is started?


----------



## jwalsh1316 (Sep 28, 2017)

The outside temper is close to accurate - it seems to be overstating hot days (e.g. park outside and it says its 105 outside when really its only 90). 

engine fan tends to scream at random times regardless of outside or engine temperate - sometimes when starting and other times when idle


----------



## jblackburn (Apr 14, 2012)

jwalsh1316 said:


> engine fan tends to scream at random times regardless of outside or engine temperate - sometimes when starting and other times when idle


That may be your issue then. There is a sensor at the thermostat and one in the lower radiator hose. If aren't showing expected values, the car will put itself in a failsafe mode, which screams the engine fan, opens the thermostat, and usually shows that A/C disabled message.


----------



## jwalsh1316 (Sep 28, 2017)

thanks but I should have clarified that the A/C disabled message is no longer showing after they fixed the thermostat issue by replacing the sensor (don't know if they touched the lower radiator hose). 

All of these issues continue to persist after the fix but there is no longer the A/C disabled message and the engine temperature on the dash is below 50% now


----------



## ChevyGuy (Dec 13, 2014)

jwalsh1316 said:


> engine fan tends to scream at random times regardless of outside or engine temperate - sometimes when starting and other times when idle


That might be due to a defective A/C - the compressor starts, the pressure goes sky high - the fan screams and the compressor drops out.

At this point, I think you're looking at a separate problem that developed while the A/C wasn't in use. At least, I'd approach it that way until proven otherwise.


----------

