In addition to faulty actuator motors, the blend door itself can also be broken. This happened on my Silverado. Typically it is a very labor intensive and costly fix to replace a broken blend door, as the dash must be removed and the plenum assembly replaced. There is a DIY kit from heatertreater.net that provides steel hardware as well as instructions on how to perform the repair by removing the glove box rather than the entire dash.


This is also an alternative to replacing the 'difficult to access' top actuator motor underneath the dash. The kit contains a single blend door which converts the dual control to single control. It is operated off of the bottom actuator motor, which can be accessed by removing the glovebox. If you are having issues with your blend door, or the 'top blend door actuator motor behind the dash' it is worth looking into.

 

I just got a 2009 Chevy Express 2500 Cargo Van. Heard the popping after I drove it home and called the dealer. They told me bring it back so they could check it out. The owner jumped in and took a listen and said it was the mode door but they wouldn't fix it as it required the dash to be removed.

They did say they would get me the part at cost. Can anyone tell me how to access the area to do the repair? The AC blows cold it only pops when switching the AC on and then maybe every 60 or so seconds.

Help!

 

Would have you have the diagrams for my 1998 GMC safari and the calibration method? Also is there a separate blend door in addition to the mode door? I would be MOST appreciative!

Thanks in advance.

 

replaced heater core and stat and still no heat running at 160 degrees.

 

I have an 05 z71 tahoe the heat works intermittantly in the front & rear unit. The front is a digital dual clitmate controller (***** w/ no stops) How do you calibrate this one?

 

I have a 2005 Monte Carlo, my a/c only blows cold/hot air only on the passenger side. What do I need to do to fix this problem? What I have read so far it could be the blend door actuator motor, if so how do I get to it to replace it? Thanks so much for any help you can give me.

 

Thank you for the diagram it was very helpful.
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I wanted to post what I found with my 2007 Uplander. Same problem as everyone else – no heat,or sporadic ac\Heat operation. <o></o>
First off, I checked all heater hose. The firewall to heater core were always nice and warm.
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Only thing that may be different on 2007; my dash console goes to the floor (center). The interior decorative pieces just pop off from the bottom. Support panel – has 8 screws and pulls out. All work done from driver side.
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after you remove bottom console - you can clearly see the heater box and actuators. You could also hold hand on heater box and feel warmth from heater core. I could hear the actuators moving, but only could see one of them actually moving ( in top Diagram Actuator #1). From what I could see of actuator #4 it looked as if it was stuck.
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Asillustrated I took the bottom of the heater box apart, it has 2 sections. First panel is sort of a vent (4 screws), the second panel enclosed the heater core (about 7 screws) .
This really didn’tdo much for me, as far as visually looking and determining if vents were moving.So I decided to loosen the heater core up (1 screw). I was able to move it to the side a little and see all vents. When I tested all heat\Ac controls, all vents were now moving. The #4 actuator was even moving and no longer stuck.
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As I was re-installing heater core screw, I had propped the other end up for alignment –when I let go, the driver side of the heater box ‘caved in’. The weight of the heater core was making the plastic bind the actuators vent rods so they could not move freely. I put a 3/16 rubber shim on opposite side of screw, re-installed that panel and re-tested; Worked fine.
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Re-installed rest of panels and a week later, outside air is 17 degree, works fine. Hope this helps someone.