A/C blows hot on driver side, cold on passenger side

[036.6turbo]

I'm looking at buying a used 05 HD. During the tset drive I noticed when the A/C was turned on, it blew hot air out of the driver side vents and cold air out of the passenger side.

It has the manual dual climate controls. I'm thinking the controller (slider switch) is bad.

Anyone ever seen this type of an issue before?

[silverado2nv]

might not be the switch but the blend doors on the hvac unit i would check it out before buying a new switch, cable could have come loose

[Yukon04]

My Yukon was doing the same thing. It would be fine if the ac was on when the truck was started, but if it was on warm air and you changed it to cool, the drivers side would blow hot. I bought a new blend door actuator at NAPA only to find the the pins for the plug were different. I put the old one back on. I was told there is a reset when you take the actuator off. Pull the ac fuse and the the key to run for at least one minute. Since I did that, it has been fine.

[036.6turbo]

Thanks for replies.

[IH8FORD]

ive seen this a couple times. the dirver side one isnt too bad to change pass one sucks. they are acuators not cable driven.

[mikeyman]

ih8ford is right. i would try the reset procedure first and then inspect the actuator and see if it is getting stuck

[TravisT]

There is also a TSB out for this. One '04 I had would get stuck on the defogger. My current truck would blow hot on pass side and cold on driver side. When you notice this happens, turn the truck off and back on, and see if that fixes it. If it does, a trip to the dealer should have this fixed.

[mikeyman]

which tsb is it?

[TravisT]

I'm a member over at dieselplace.com, and that's where I have seen the TSB. I looked today and couldn't find the actual TSB, but I have had my truck in and it was fixed with a reflash on the tech2.

I also noticed today that there are several people on DP that say you can disconnect the battery and sometimes this will reset the computer and eliminate the prob. I have also heard that if reflashing the bcm doesn't work, then the dealer will replace one of the a/c door actuators or something.

I really wonder about the service departments these days. If the computer doesn't tell them what's wrong with the vehicle, they are completely clueless on troubleshooting the problem. Hope this helps!

[Yukon04]

I read on here a while back that the vehicles with automatic climate controls, with this problem, need to be hooked up to the computer at the dealer to be re-programmed. The vehicle computer opens the blend door too far, causing it to stick. Re-programming it takes care of the problem, in most cases. The manual controls can be reset by pulling the HVAC fuse and turning the key to run, without starting, for one minute. Turn the key off and put the fuse back. That's what I did and it has worked fine since.