Ford Windstar Heater blend door actuator problem

Hi all. I have been reading on several articles about ford’s blend door actuators on this forum (it’s a fantastic forum). I have a 96 Ford Windstar with heater problems. Sometimes it blows cold air. To get to the components I had to remove the cover around the temperature controls. I have been in electronic for many years so I try to find all the information I can. Hopefully this will help someone. First, I found a PDF file on line that will help you trouble shoot. It is located at:

http://www.carquest.com/common/downloads/partsTechTempcontrolCR356%20Ford%27s%20Blend%20Doo r%20Actuator.pdf.

Now what it does not tell you.

1. Pins 1 & 3 of the Temperature Control Potentiometer are the two ends and its resistance is approximately 4.6 KΩ. Pin 2 is the arm.
2. Pin 1 is approximately 9.5 Volts and it connects to pin 4 of the blend door actuator.
3. Pin 3 is at zero volts and connects to pin 6 of the blend door actuator.
4. Pin 2 varies from 0.3 V (hot) to 9.2 V (cold) and it connects to pin 3 of the blend door actuator.

If you vary the temperature control very slowly either way, the voltage will follow. If the voltage jumps around then the temperature control switch is bad. If it is quiet, you can also hear and see the motor shaft rotate. At least for me I could. If you do not have voltage at pin 1 of the Temperature Control Potentiometer, check to see if you have voltage at pins 4 (9.5V) & 7 (12V). If pin 4 is at 12V then pin 8 is probably not grounded.

Hope this hepls.
Bob