I'm having a problem with my dual climate control, and this pertains to both the drivers side and passengers side responding in exactly the same way. When set to 90 degrees, the heat works great. However if I adjust the temperature to 89 degress, it responds like I've set it all the way down to 60 degrees. Both sides as I mentioned respond the same way.

SOURCE: 2004 chevy tahoe, dual climate control, blowing different temps

Its more then likely the temp door broken or temp door motor broken/stuck. There is 2-3 of these motors under the dash on the side of the evap/heater core box. Some require extensive labor to replace, good luck

SOURCE: driver side ac blows hot and passenger side blows

check your vacume units for the door actuators . some units have a plastic gear drive and the unit has to be replaced on the change over door arm .

Jeffrey Turcotte

• 8991 Answers
• Posted on Oct 31, 2010

SOURCE: the heater/vent system will not blow warm/hot air

On a newer truck such as yours, the problem is usually the blend door actuator. First try a recalibrations of the system. Remove the HVAC fuse for a couple minutes and then put it back in. Start the truck and let it idle for a few minutes. Check to see if that fixed it.
If not, next check the actuator. I will paste instructions below for taking it out. Once you have it out, plug the connector back in and see if it turns when you change the temperature control. If not, the problem can be in the controller or the actuator. If it is clicking, the problem is stripped gears. If it isn't doing anything, you can check for voltage at the connector with a voltmeter. Connect the black meter lead to a good ground point and probe the connector terminals with the red lead while changing the temperature setting. The part costs $140, so do what you can to make sure it's bad before putting a new one in. Also, it may be worth your time to read my post at http://www.fixya.com/cars/r6235876-no_heat_fan_blowing_cold_air for other ideas. Please let me know if you have questions.

1. Remove the floor air outlet duct extension (1) from the floor duct (2).
   

Fig. Remove the floor air outlet duct extension (1) from the floor duct (2)

2. Disconnect the electrical connection at the blend door actuator (10).

Fig. Blend door actuator and related components

3. Remove the blend door actuator mounting screws from the HVAC module.

4. Remove the blend door actuator as an assembly with the actuator cam.


Fig. Remove the blend door actuator mounting screws from the HVAC module