My mistake, it is grey.

 

That is the "slave door actuator". It directs all airflow through the heater core in the HEAT position. The vacuum line should have vacuum in the OFF and HEAT positions only.

 

So I was curious yesterday. So I pulled my new blend door actuator out and took it and the old one apart. I didn't see anything wrong with the internals of the old one. Here are some shots of the 2

Old


New


Side by side


The new one does not have the blue gear that the old one has. So I put the old one back in and now I have hot and cold but it is hot only when it is turned all the way up and cold on everything else in the temperature range, like this.


This is exactly how it was before, but at least I don't have just heat now.

 

There are 2 different actuators: with and without automatic climate control. They are nearly identical in appearance, except the number of terminals is different, and of course the part number. Are you sure you have the correct one?

 

Both of them have 5 terminals. According to the seller this is for the automatic climate control.

 

You need to have it checked for DTC's and run the functional tests. It will be tough finding an independent shop that is experienced with the ACC system, and willing to tackle it. Any GM dealer should be able to diagnose it for you.

 

The seller is letting me return the part. Also the shop my father works with said he can scan BCM codes, but that might take a while since he only works 1 - 2 days a week.

 

Make sure it is a bidirectional scan tool so you can do the functional tests.

 

Thanks for the heads up. I will ask him to do that. I really appreciate all of your help Captain!

 

I know this is bringing up almost a year old thread. I did have my Dad's guy scan for codes when he inspected the car. He said he there were none in the BCM.