A/C and Heat

[privatejb]

I have a 2004.5 lly when I turn on the A/C one side of the dash will blow heat and the other will blow A/C. Both nobs are turned down to 60 degrees and everything is on the correct settings. It only does this sometimes then will stop for a couple of days. Has anyone heard of this problem before.

 

[Krazykid]

I have a 2004.5 lly when I turn on the A/C one side of the dash will blow heat and the other will blow A/C. Both nobs are turned down to 60 degrees and everything is on the correct settings. It only does this sometimes then will stop for a couple of days. Has anyone heard of this problem before.

I had this happen over the 4th of July on a long trip back from PA. Turned the passenger side which was set to 60 and blowing heat to 80 for a few sec and then back to 60 cold air started blowing again. I think it has to do with the BCM either needing to be re-programming or replaced. Good luck and keep us posted on what you figure out.

 

[DAVe3283]

Yeah, sounds like the symptoms of the blend doors. If you search for that, you should find lots of information. If I recall, you basically have to replace a actuator and it will be fixed.

 

[06blackmax]

Sometimes you can have the climate controls reflashed, but most of the time you have to replace the servo motor on the door. Be prepared part is about $200.

 

[68skylark455]

First thing to do is pull the A/C fuse and the HVAC fuse in the inside fuse panel by the drivers door for atleast 1 minute. Put them back in turn on the key to just the run position without starting it an leave it there for 1 minute. Turn it off then back on and start the truck. Try your a/c now. there is an update for the bcm for this problem but only a dealer can do it. If this workss have the update done. If it keeps doing it replace the main actuator with the wheel assembly above the gas pedal.

 

[privatejb]

thanks guys for all of the ideas i am going to try them today.

 

[duramaxxx06]

you ever have any luck with this?

 

[Darius6t9]

The Actuator above the gas peddle was only about $75 when I got it last year. Turned out that I didn't need it tho. It was a wire stuck in the gears. But that was the actuator for the foot/face/defrost blend door.

Rockauto has a Heater Blend Door Actuator for $43.79 and one for $109.79.


wow. guess I should have looked at the date. oh well. still good info non the less.