Ac not still on

[richump123]

Ok guys I have a 2004 Yukon slt with digital climate control, when I start vehicle and turn ac on, it only blows cold for about 10 seconds then changes to heat, I've tried recalibration with no luck. Any ideas what could be causing this to happen? Actuators seem to be working, cause usually when seasons change I get Actuator to hot or cold then pull plug on Actuator under passenger panel but tired of doing this. HELP PLEASE

 

[B-train]

Do you hear the compressor kick on? If so, does it only stay on for the 10 seconds and then never cycle again? Or, does the compressor come on and stay on, but the blend door malfunction and default to heat? Can you choose defrost mode and get cool air when commanded?

You might need a new contract panel. I think they are cheap enough these days as a try it and see sort of deal if nothing else seems to make sense.

 

[rockola1971]

First verify compressor clutch is engaging and if it is verify refrigerant pressures low and high side. There is a low pressure switch that locks the compressor out if you have lost too much refrigerant (and also lube oil which is mixed with the refrigerant).

 

[OR VietVet]

Yep, basics first and verify the compressor operation and the pressures. Those actuators have been known to make a guy/girl pull their hair out though.

Welcome to the forum.

 

[RAMurphy]

Welcome to the forum. Great advice here.