So it seems that i may have a blend door on the fritz. All the settings on the HVAC control panel seem to work - blows cold (or hot) everywhere as selected. But when I press the recirculation button the light comes on but i do not hear any change in fan output as usually accompanies this process. I looked at a couple other threads about the actuators but they all seem to address the "hot on one side/cold on the other. I don't have that issue. I just want it to change from the outside air to recirculating the inside cab air. So is the actuator I need to troubleshoot the one up under the dash (yellow circle) or the one under the glove box area (purple arrow)? Or possibly any way to check the controller which seems to be functioning correctly? TIA folks.

 

That is the hardest one to get at. It can be done without removing the entire top of the dash if you remove the grab handle and airbag but is very difficult and you are working blind. If you flip the glovebox all the way down (pull tab on right side when open to do so) you can look up and towards the firewall and see the door that opens/closes. I believe there are some modes where it will not allow you to switch to recirc. If you have a Tech2 you can get into the HVAC tests and verify it it is even trying to open.

 

So you're say the one way up under the dash pad (yellow circled area). Don't have a Tech2 so will have to find a shop that can do that. Thanks for the info.