I have an 06 trailblazer ext Lt package with electronic front and rear hvac controls. My rear hvac system will not read the blender door actuators. I've replaced both actuators with ac Delco and gone through all the resets. I have also taken to the dealer and they can't get any communication with it as well as I have tried a scan computer and can't control as well. I'm at a point I believe it may be due to the result of a sector in the BCM may have gone bad. I've also thought about figuring out how to straight wire the actuators to toggle switches to bypass the bcm to control the actuators. When I plug the actuators in and do the resets for them, I can watch them move and function. But once the reset is done they don't work period. I've even replaced the controllers with new acdelco controllers and still same issues. Any suggestions?

 

The first thing I would do is to remove and then reseat the connectors that go into the BCM. A bad electrical connection can cause what you describe. If the contacts on the BCM or the ribbon connectors look dirty, you need to clean them - very gently!

I recommend the use of this product from DeOxit:


This stuff works wonders. It will clean and remove any oxidation, and it leaves behind a residue that enhances the conductivity of the electrical contacts. I've used it on my 2004 TrailBlazer's adjustable downward side mirrors with great success and in several electronic repairs.