So, I did my blend door actuator yesterday (I have the auto AC system). The problem I was having is that I had heat when it was all the way up, but as soon as I turned it one notch down I only had cold. So now that I have the new motor in I only have heat. No matter where I set it. Didi I install it wrong? Or do I have a bad actuator?

 

Did you recalibrate the actuators?


Remove the RDO BATT fuse for 10 seconds and then reinstall the fuse.
Put the ignition switch in the RUN position and wait 40 seconds for the ECC module to initialize.

 

I did that this morning, no luck. I will try again this afternoon.

 

I just tried it again on my lunch break and I still only have heat. Never had these problems on a car with a cable driven heater core valve

 

Nope, and those systems won't do what your ATC system can do when it's working properly


You will need a bi-directional, (high end) scan tool that can access the BCM. You'll need it to retrieve trouble codes, help diagnose the system, and perform functional tests. Or you can keep guessing which part is bad


BCM DTC's will NOT turn on the check engine light.

 

I have scan xl pro on my laptop but I don't know if it would read those codes.

 

I just re-read the how to thread how to do the blend door actuator and noticed something. The vacuum actuator that is in front of the blend door actuator, what does that operate? I noticed that mine is no longer connected to anything. The plastic arm that it connects to looks like it is broken off. I noticed that when I replaced the blend door but then forgot about it after the entire ordeal.

 

What color is the vacuum line on the actuator?


EDIT: Scan XL Pro is a step above entry level scanners, but even their
"Enhanced GM" upgrade will not access the BCM.

 

black.

 

Unless it has been replaced, black is typically the vacuum source. It should have vacuum in every position of the mode switch with the engine at idle. The manual HVAC system, and the automatic climate control, both use electronics to control temperature, not vacuum. Really think you need a capable scan tool for this one