2004 yukon rear A/C blowing hot air

[samwaite]

I noticed yesterday that my rear a/c is blowing hot air, but intermittently. After I fiddle with the switches, start/stop the a/c, and sometimes shut down and restart the truck, it will work properly. Is there an actuator or relay I should suspect? The fan works fine, the front a/c works fine, it's just the rear a/c that will blow hot air (pretty warm, not just uncooled air) sometimes. I don't hear any telltale noises that clue me into anything, just that it sometimes does or does not work.

[8.1HD/ALLISON]

Probably the rear air temp blend actuator. The sensor inside them tend to loose place and do stupid things.

[samwaite]

that makes sense, because when it acts up, the air is pretty warm, not just recycling cabin temp air. I suspect it's getting heated air. Do you happen to know if the actuator is servicable, or just has to be replaced?

[GMCustomerService]

Looks like you have received some good advice. Keep me posted on your progress. I would also be willing to look into this for you on my end with the last eight of your VIN. Please feel free to contact me for more assistance. Thank you.

 

Tricia, GM Customer Service.

[MVP.in.AZ]

I had a very similar problem with my 2004 Silverado 1500. Try looking at this thread ( http://www.gm-trucks.com/forums/topic/67578-ac-goes-to-heater-mode-by-itself/ ) and following the advice of yfrankiii and parrdaddy.

 

I took apart my air blend actuator, and after cleaning up the grease inside on the electrical connections, it works like a charm. Didn't cost me a penny, only time, a half dozen q-tips, and some rubbing alcohol.

[grampadirt]

If the above doesn't work it may be the rear expansion valve,happened to me.