Tring to fix my rear HVAC. Hot/Cold change over not happening

[chip]

You know what? You aren't even going to believe this, but somewhere around here, somebody gave me the idea to disconnect the battery. I was reading something about the control doors reverting to a default position after a disruptive evet, and the only way to reset them, was to reset one of the computers. I said **** it and disco'd the battery for 10 minutes and made sure all ICs were dead.

I reconnected the battery............and wouldn't you know it, everything started working fine again. So I don't even know if I necessarily needed the actuator in the first place.

I STONGLY SUGGEST trying this before you buy anything. Anyone who is having this issue.

 

[a4edwin]

How do you remove that panel?

 

[cruszala]

Rear HVAC

Don't know if you ever fixed the rear HVAC problem you were having. I had the same thing the mode and hot/cold were not working. Stuck on Hot and floor. I have an 06 with auto climate control. I bought a new actuator and control module (blower resistor unit) and still no working rear HVAC . Turned out I had the 4 pin actuator installed by accident on the mode and when you unplugged the actuator the blower fan seemed to pick up speed. So I bought the 5 pin, and then the mode door began to work but nothing on the hot/cold. So I swapped them around , pulled the fuse and unplugged from the control module. Went to the front seat and got no change in Hot/Cold from the overhead controls. I changed the settings to AUX, went to the back seat and all of the sudden the Hot/Cold began changing. So I removed the overhead control unit, blew some compressed air in the unit and now the overhead control works. Apparently there was some dust built up preventing a good connection in the overhead unit. It has been about 2-3 years since I have had rear HVAC control and it feels good once again. Just thought I would share what worked for me. Good Luck.

 

[Yukon Lover]

Thanks Cruszala. I was wondering when someone might start posting here again. I had issues with just the hot/cold switching but after messing around now both actuators dont cycle they went all the way to one side so now no mode action either. Havent looked at it in awhile cause it aggrevates me and its freezing ass cold out now.

 

[Rtking73]

I have a 2004 Tahoe that I replaced the Control Module on, and I am still having a problem with the blower running even when the car is turned off. Would it be best for me to unplug the battery and try the reset first? I am wondering if the wiring harness has gone bad on it, but am having trouble finding replacements.

 

[Yukon Lover]

So your rear blower stays on all the time? I would go for the rear blower control switch. You could try the reset as it's the cheapest and easiest thing to do. You could try the compressed air thing on the overhead control as Cruszala said if the reset doesn't work.

Sent from my Z797C using Tapatalk

 

[Brake_L8]

Might as well pile on to this thread as I have a unique issue involving rear HVAC. Mine started blowing hot air one day when set to full cold. Front AC is fine. I tried the overhead panel and the rear controls, both took my input but no change in temperature from the rear vents.

Roommate and I pulled apart the rear HVAC in the cargo area, where all the controllers are, as I thought the issue might be the blend door controller or whatever. Well, it seems like my actual "knob" thing -- the piece that gets rotated by the electric module to change the blend door -- has broken. It seems like it was most of the way there, then I touched it in an attempt to manually change the blend door, and it fell into the HVAC box.

So now I guess my next steps are to undo everything attached to that stupid box, open it up and try to replace or repair that rod.

Anyone else deal with that issue?

 

[Cash_88]

I recently pulled my headliner I have a '03 hoe with rear air and digital front. As soon as I got in to go to work the rear blower stayed on. The harness to control it overhead is glued to the headliner so I had to trace to to the fuse box left of the brake pedal and remove the two plugs with it. I just unplugged the motor directly since it is fully gutted anyway besides the two front seats and center console. I'm guessing with no reference from the overhead console it decided to come on lol. Replacing the temperature actuator back there is on my to-do list before I button everything up.

 

[treymon]

Brake_L8
did you have any luck fixing your issue? I just took my yukon apart and have the same broken pin that you are talking about.
any advise?
thanks

Might as well pile on to this thread as I have a unique issue involving rear HVAC. Mine started blowing hot air one day when set to full cold. Front AC is fine. I tried the overhead panel and the rear controls, both took my input but no change in temperature from the rear vents.

Roommate and I pulled apart the rear HVAC in the cargo area, where all the controllers are, as I thought the issue might be the blend door controller or whatever. Well, it seems like my actual "knob" thing -- the piece that gets rotated by the electric module to change the blend door -- has broken. It seems like it was most of the way there, then I touched it in an attempt to manually change the blend door, and it fell into the HVAC box.

So now I guess my next steps are to undo everything attached to that stupid box, open it up and try to replace or repair that rod.

Anyone else deal with that issue?

 

[mizzouguy]

Might as well pile on to this thread as I have a unique issue involving rear HVAC. Mine started blowing hot air one day when set to full cold. Front AC is fine. I tried the overhead panel and the rear controls, both took my input but no change in temperature from the rear vents.

Roommate and I pulled apart the rear HVAC in the cargo area, where all the controllers are, as I thought the issue might be the blend door controller or whatever. Well, it seems like my actual "knob" thing -- the piece that gets rotated by the electric module to change the blend door -- has broken. It seems like it was most of the way there, then I touched it in an attempt to manually change the blend door, and it fell into the HVAC box.

So now I guess my next steps are to undo everything attached to that stupid box, open it up and try to replace or repair that rod.

Anyone else deal with that issue?

I've got the same issue. Any luck?