1969 Plymouth Subarban Tailgate power window problem

[7071 chally]

Hi guys... I'm working on a friend's 1969 Plymouth Subarban and the power window is not working in his tailgate. He replaced the motor (that came from a 72 Monaco wagon). If I apply power to the motor, window moves up and down. I had no power at the power assist relay, which is now fixed. I have 3 wires at the switch (Tan, Red, Yellow). When the power assist relay is energized, I have power on the Red wire at the switch. If I flip the switch up, I have power on the brown wire way down to the tailgate motor, but the motor is not moving. If I flip the switch to the down position, I now have power on the yellow wire way down to the tailgate motor, but motor is not moving. The thing is, I'm getting no ground to the motor. When the brown wire has power, the yellow wire should be a ground and vice versa. If I disconnect the switch in the cluster and I apply power and ground to the yellow and brown wires (at the switch plug) motor turns fine, so the circuit is good. I checked the wiring diagram and I can't figure out how the motor should get ''down'' or ''up'' ground. I have power the ''Up'' and ''down'' position, but I never have a ground. How is the circuit suppose to send a ground to the motor? Am I missing something? TIA

 

[cbarge]

Body is ground.
There is no ground wire per se.
Red wire is hot power.others are up and down.

 

[marko]

does it not work from both the outside key and the dash switch ?
my 71 custom suburban's window works, but the tail gate key switch can be abit fiddly at times.... i just put it down to the wiring connection to the key switch needing some attention

 

[7071 chally]

Body is ground.
There is no ground wire per se.
Red wire is hot power.others are up and down.

Ok, that would make sense but it doesn't work and I do have power to the motor. The guy told me the motor he installed came from a 1972 Monaco wagon, so now, my guess is that the Manaco motor uses a different harness and switch. I will have to check the wiring diagram for a 72. Thanks!

 

[7071 chally]

does it not work from both the outside key and the dash switch ?
my 71 custom suburban's window works, but the tail gate key switch can be abit fiddly at times.... i just put it down to the wiring connection to the key switch needing some attention

Yes, there is an outside key that can operate the tailgate window.

 

[Wonderwagon]

If you have not checked, and memory serves me. There is a safety switch on the "latch" side of the tailgate when used as a door. little inset silver thing, middle of side frame. Sorry best description.

 

[7071 chally]

If you have not checked, and memory serves me. There is a safety switch on the "latch" side of the tailgate when used as a door. little inset silver thing, middle of side frame. Sorry best description.

I did check it, it's called a limit switch.

 

[7071 chally]

I checked the 72 wagon wiring diagram (because the 69 Suburban has now a 72 tailgate motor), and the 72 has a different tailgate window switch that also sends a ground, but the 69 doesn't, so, to make the story short, the 69 motor and 72 motors are different electrically wise, so, if we find the right motor, everything should work. Thanks everyone!

 

[3175375]

I checked the 72 wagon wiring diagram (because the 69 Suburban has now a 72 tailgate motor), and the 72 has a different tailgate window switch that also sends a ground, but the 69 doesn't, so, to make the story short, the 69 motor and 72 motors are different electrically wise, so, if we find the right motor, everything should work. Thanks everyone!

I would suspect that you could make it work...

 

[marko]

yeah and in 72 they changed some details of the tailgate - it has an outside door handle that the earlier ones didnt and you can also open it in door gate mode with the glass up but you still had to put the glass down to open it as a drop gate