I am reinstalling the headlights, brackets, pivots, etc after having the car repainted. All works well on the RH side. Headlight lights up and it opens and closes. On the LH side the headlight lights up in the closed position. It will not open and close. I have replaced the relay with one I know is good. The ground wire is tight. No blown fuses in the fuse panel. The nut that holds the lever to the splined post on the motor seems tight enough. If I manually turn the black knob at the back of the motor, the light will cycle open and then close.
Electrical problem somewhere?
What do the 3 wires do that plug into the 3 wire plug coming from the motor?
Red = power? Does this wire give power to the motor AND the headlight?
Green???
Gray???
I thought headlight motors were pretty much bulletproof, last forever. Maybe not.
If anyone has a suggestion on how to attack this problem and what I should look at first, please let me know. . Thanks in advance for the advice.

When you manualy cycle the head light with the black knob does it take over and go through its cycle? If so bad headlight switch . If not bad motor or connections to motor.

Old thread from search...I am experiencing this on the driver side; passenger side works fine.

The motor does take over when I turn the knob.

Is it really a switch issue?

The wires for both motors are common, , if one motor works, the headlight switch is good. . the wires from the switch go to the drivers side motor first and T off there over to the passenger side

Colors are red green/bk and gray on my 1970, same as yours. . . . although the factory manual states they are red, blue and black, in my 1972 edition [page 3.2 2-2]

When you operate the headlight switch, it puts
+12 Voltage to Red and Gray and make the motors run to the 'up' position. . they stop at the up because slider contacts inside the motor gearbox break the connection and the motors stay 'parked' . . . When you turn off the headlight switch, to go down +12 volts is applied to the Red and Grn. . the motor will run to the 'lowered' position;

I'd remove the operating bar that goes from the motor to the headlights to make sure it's connected in the proper position. . if it is on 180 degrees out, when you turn on the motor, it is trying to lower the headlight and it will bind. . once the motor is running, then you can figure where the connecting bars should go in relationship to the motor output shaft. .

Notice the attached specifies to only connect the bars with the motors in the raised position