One of my headlights tries to open, moves then drops back down, the manual "knob" still spins for about 5 seconds both direction, when opening and when I shut the lights off, since the motor is obviously running what is the issue and what is the fix?
This sounds like an 84-86 motor, so i'll base my comments on that.
If you can open the hood, grab the headlight and lift, causing the motor to finish the lift, then you have a gear with 3 or 4 teeth stripped off at the bottom end of travel.
If the headlight won't raise, even with manual help and the motor continues to run, the drive plate for the gear has probably come loose from the shaft. This is an unusual happening unless the motor has been previously rebuilt. That can be determined by screws and nuts holding the two halve of the motor case together. If it still has the rivets, it's possible that the fingers on the drive plate have broken off due to the disintegration of the bump stops.
It would be a good idea to disconnect the single blue wire with the barrel connector and raise and lower the motor manually by sticking a ball point pen or small screwdriver into the dimple in the knob and spinning it. By using this method, you can more rapidly raise or lower the light than you can by using your fingers.
Motor rebuild service using Rodney's metal gears are $30 labor for each motor. Cost of gears and return shipping are added without markup. Workmanship guaranteed for 1 year. Email or PM me if you are interested.