Mode door actuator location

Good morning,

NOTE: If battery voltage is low or not sensed at the actuator/motor for less than a (60) second interval, the actuator/motor will be out of calibration. Remove the M1 (I.O.D.) Fuse for a minimum of (60) seconds. The actuator/motor will then self calibrate itself upon reinstallation of fuse.

The mode door actuator is an electric motor. It mechanically positions the A/C unit panel/bi-level door and the floor/defrost door. Prior to part replacement, re-calibration of the HVAC actuator is recommended. Calibration is performed by disconnecting the battery negative cable or the removal of the instrument panel M-1 fuse. Electrical power should be re-established after (60) seconds which will automatically initiate the software calibration procedure. If this procedure fails, it will be necessary to replace the mode door actuator/motor. The mode door actuator/motor is not serviceable and must be replaced if found to be defective.

The mode door actuator is located on the upper left side of the A/C-Heater housing.
REMOVAL
1. Disconnect battery negative cable.
2. Remove left underpanel silencer/duct.
3. Remove electrical connection on actuator.
4. Remove actuator retaining screws. Then pull actuator straight down. Upon removal, note the shaft position of the actuator, because the shaft on this motor is keyed. When installing new actuator, its shaft must be positioned in the same location.

INSTALLATION
For installation, reverse the above procedures.

See pictures below

The easy way to test the pot is to measure the resistance across the two outer pins, then the resistance of the sweep finger as it moves. The motor itself is a five volt unit.
One thing to always try with those systems is to re-calibrate it before replacing the part. They seem to "forget" their position quite a bit.
To do that you remove fuse M1 in the instrument panel box. Keep it out for at least a minute. Reinstall and the system will re-calibrate the door positions.

It sounds like you may have a bad controller mode switch. It uses a voltage drop through it to determine the position of the controller as well as preset resistances in the switch. I am guessing you tried another controller already?
Maybe these schematics of the system will help.

Voltage sounds low, what do you get on the red mode sense wire with the controller unhooked? You should see 5 volts between it and a good ground.

It would not be the first time a component tested "good" but actually did not work. You could go to a salvage yard and get a used actuator and try it. New they are $60.00+.

I have done worse, I had one that the blend door actuator was expensive so I connected a manual cable to a simple lever and moved it that way.