First, remove the center panel:
- Remove the boot panel, ashtray, and the center louver.
- Remove the center panel attaching screws (two behind the vents, two behind the ashtray), then detach the center panel from the instrument panel.
- Remove the cigarette lighter illumination bulb unit (twist to remove) and the cigarette lighter connector.
- Remove the center panel.
Remove and unplug Logicon.
Testing the Air Mix Motor:
On the other end of the plug/harness that is attached to the logicon, (the plug that the harness attached to the logicon plugs into) there is a green/white wire and a solid yellow wire.
To get to this plug, you will need to remove the instrument cluster (speedometer, tachometer, etc display) which is underneath the gauge cluster (click here for how to remove it).
NOTE: Some people are able to get this plug from below, starting from the area near the gas pedal.
After removing the gauge cluster, remove the four screws holding in the instrument cluster then reach behind it and unplug the connections. You can now reach in and access the plug, which is underneath the idiot cluster (clock/warnings display).
Using a digital multimeter, the resistance between the Green/White and the Yellow should be 17 to 21 ohms, if the motor is good.
If you put +12V on the Green/White while putting ground to the Yellow and the air/mix motor is working, it will move all the way to the cold position.
Reversing the two (+12V on the Yellow, ground on the Green/White) will move the air/mix motor to the Hot side.
If applying voltage either way doesn’t move the air mix motor, it is bad and requires replacement. If applying voltage does move the motor, the logicon is bad or the connections to it are bad.
Testing the Air Mode Motor:
Find the large plug above the air mix motor and unplug it. We’ll be testing the wires on the car side of the harness, not the side going back to the logicon.
There will be a blue/yellow wire and a green wire. Using a digital multimeter on the two wires, you should see between 17 and 21 ohms of resistance.
With +12V on the blue/yellow and ground on the green, the mode motor should move all the way over to the vent position. With +12V on the green and ground on the Blue/Yellow, the mode motor should move all the way over to the defrost position.
If applying voltage either way doesn’t move the air mode motor, it is bad and needs replaced. If applying voltage does move the motor, the logicon is bad or the connections to it are bad.