What's the possible causes for AC to quit blowing cold air overnight?

Asked by Aug 30, 2015 at 01:35 PM

Question type: General

I have a 2004 Yukon XL Denali in which my AC just quit blowing any cold air overnight.  All fuses seem to be good and refrigerant level is good.  the compressor sounds as though it engages when AC is turned on.  I'm at a loss?

2 Answers


Is fan blowing? If so possibly bad actuator motor or blend-rec door issue.

Best Answer Mark helpful

ok ok here might be the problem there is a unit under the dash that controls the door movement inside the heater bomb. this unit opens the door to the ac core and the heater core. if you have the ac on and blowing and the door is closed you will get heat out the vents. I have added a picture. here is what you can do under the passanger side of the dash you will see the item in the picture might have to remove a cover pannel to look under dash. have some one turn on the ac and then the heater and see is the little white wheel is turning if it is then we will have to go a different rout to fix if it is not turning then this is the problem and I have seen alot of these go out. hope this helps oh ya by white wheel I mean the hole looking this at the top . this is the blend door actuator if you need to order one.

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