What I mean by intermittent is that mostly I can’t get heat into the car but occasionally the heater will just start working, only to have it not work the next time I use the car. I replaced the electronic climate control module about two years ago. Old unit was completely dead when I purchased the car. All of the functions appear to work correctly as far as fan speed, temp controls, defrost, front vents and floor vents and in AC mode.
On top of the air box is the blower motor resistor. If I remove this and look into the air box, I can see a damper door which controls when air is allowed to come from the heater core into the air box. This appears to be what is causing the problem. If I wedge the damper door open, I can get heat into the car, but I’m unable to adjust the temperature other than just shutting the thing off.
Because it works occasionally, I’m assuming there’s some sort of sensor that controls this thing but I’m at a loss trying to figure out what or where it is. The outside temperature sensor does appear to work since I can get an outside reading on the control module and the AC seems to function correctly.
This thing has been a real pain in my butt and hoping someone may have come across this problem before or can point me in the right direction.

 

I don't know but it sounds more like a loose connection somewhere. Most intermittent issues are connection related.

We'll bump this up for the experts to take a peak.

 

Assuming Electronic Controls, it's controlled by a motor that's attached to the door with a plastic clip. More than likely, that clip is broken. Remove the Passenger side Hush Panel and ECM to access the motor which is on the Heater Box.