New motors, limit switches, wiring harness, relays and bushings. Doors open and close like they are supposed to. The problem is whether the doors are open or close, they hit the limit switch and the door bounces back and forth and the motor will not shut off. I can push on the door and hold it against the limit switch and it will stop. But when I let go, the door just bounces back and forth off the switch. Any idea on how to fix this?

 

Does anybody know if the limit switch is a on and off switch or a momentary switch?

 

On/Off switch.
When headlamp switch is activated, open or closed, the door swings in the selected position.
At the end of travel, door opens power to motor and door stops.
When opposite direction is selected at h/lamp switch, another route of reverse polarity power to motor and door goes to direction selected.
Door hits other limit switch and door power supply is opened.

I suspect wiring is wrong.
The above would be for a '67 as door motors are electric.
Sixty-eight and newer are vacuum operated.
You may have a leaky solenoid/valve or not enough vacuum from engine, need at least 13 inches of vacuum, for holding door closed/opened. Reservoir has no leaks?
Hoses in good shape? No cracks?

 

I think I found the problem. The shaft on the motor is slotted. Then there is a slotted washer, door arm, another slotted washer and a nut. Both washers are rounded out. Thus the play in the door. (New washers). All 4 washers are bad. So I can take a chance and buy new washers. But I decided just to spot weld the arm right to the shaft. No more play. Will have to wait till saturday to put it all back together see how it works.

 

Cool beans. Keep us informed the results.