2004 Chevrolet Monte Carlo

Heater problem
2004 Chevy Monte Carlo 6 cyl Two Wheel Drive Automatic 85000 miles

Our car has the dual temperature zones and we are currently not getting any heat to the driver side. This seem to be a pretty common problem affecting the temp door actuator (most likely) control panel (possibly) or wiring/vacuum tubes (least likely). Based on you experience what part should I buy first? I would like to have them on hand so I don't have to rip the dash apart twice. Also, can you give me a good description on how to locate/replace the temp door actuator? Chilton or haynes don't say much about it Thanks!
September 29, 2009.

Blend door actuator is the most common and I would start by checking it.

Sep 30, 2009.
I had the same problem with my 05. At first I thought it would of been my left side temp actuator so I went ahead and removed it. I tested it out with 4D batteries and it still moved back and forward. Then I tried moving the blend door with my hand in place of the actuator. I felt heat come out on the floor. So I assume that the door was jammed on something or just stuck. So most likely it's your blend door which is a very easy fix. You will have to remove the knee bolsters under your steering column to get to the actuator. It'll be placed toward the center of the dash. You'll be able to see it if you lay down on the floor on the drivers side.

Oct 15, 2009.