Dual Climate Control works only at 90 degrees

My 04 Tahoe Dual climate control on dash blows cold air. When I turn the knobs from 60-89, it blows cool air but when I turn it to 90 degrees, it blows warm air. The controls on the ceiling work for blowing warm and cool air in the back of the vehicle.
Would you think that a temperature sensor above drivers head is bad or the climate control module unit itself ?
Or should I disconnect some fuses or battery for awhile and see if it resets itself?
Thank you.

My 04 Tahoe Dual climate control on dash blows cold air. When I turn the knobs from 60-89, it blows cool air but when I turn it to 90 degrees, it blows warm air. The controls on the ceiling work for blowing warm and cool air in the back of the vehicle.
Would you think that a temperature sensor above drivers head is bad or the climate control module unit itself ?
Or should I disconnect some fuses or battery for awhile and see if it resets itself?
Thank you.

Has battery went dead or been replaced or any other work been done on it?
To reset key with off remove raido fuse and reinstall.
If that does not help.
You need to get it on a good HVAC capable scanner and check for codes and operation.
Post bacvk any codes.
MT

The battery has not gone dead since we have had it. I have only changed the fluids and spark plugs. Why do we reset the radio fuse? Is that circuit tied into the climate control circuit?

Thank you very much. I will give that a try.

The radio fuse supplies power to ac controls.
Removing it recalibrates your actuator motor for ac controls.
If that does not help you need to get the body computer codes.
And post back codes.
MT

With the key out, I pulled the radio fuse and now the passenger gets heat but the driver side is still cold air. The passenger side just blows a constant heat. It does not seem to regulate with control.
The drivers side, 10 minutes after resetting the fuse blew warm air for a couple of seconds and then I had to shut it off because we had to go to church. When we came back out it blew cold air.

Also, after pulling the fuse, the passenger side blows constant heat and the air conditioning will not blow cold air on that side. It worked before the fuse pulling.

That tells you it was not calibrated to start with.
Does the auto temperature work now?
Also the auto dual control system is very sensitive to the proper R-134a charge.
Get a set of AC gauges on it and post back low and high side readings at idle and at 2K rpm.

If controls reset and it has the proper ac charge and still does not work right.
You will need to get it on a BODY CAPABLE SCANNER.
And post back codes.
MT

The blower blows where it is supposed to(up or on floor,etc.)
The driver side blows cool very cool air 60-89 degrees. At 90 it blows warm air.
The passenger blows warm air at all degrees. And now Air conditioning on passenger side does not work after fuse reset.
The drivers side stayed the same and the passenger blows constant heat now at all degrees but not variable.

Like compressor does not run?
If running check low and high side pressure readings.
Post back pressure readings.
What codes is it setting?
MT

[quote=touchlinc]The blower blows where it is supposed to(up or on floor,etc.)
The driver side blows cool very cool air 60-89 degrees. At 90 it blows warm air.
The passenger blows warm air at all degrees. And now Air conditioning on passenger side does not work after fuse reset.
The drivers side stayed the same but will heat at 90 degrees and the passenger blows constant heat now at all degrees but not variable.

I will have to take it in and have a body capable scanner done.
Thank you

The wiring between the temp control sensor above Drivers head and the climate control module had a short or bad ground. Instead of tearing the headliner out, they grounded that circuit in another place and now the dual climate controls work.

Thanks for the help and input.

Ok so I was just ran into this problem for the first time and it turned out to be the air temp sensor located in the cab of the truck just above the drivers head the gm part number is 22834330 It controls the actuators to control the temp control . this was on a 2003 chevy silveado 2500 hd 6.6