[johnta1]

1st, the motor has to be grounded. If it has lost it's 'ground' it will not make a complete circuit. Maybe try adding a ground wire from motor frame to chassis ground? Then apply 12 volt to the blue 'up' wire?

Never seen a GTO PW setup, but on Firebird, I think the motor and regulator have to come out, then the motor separated?

Plus it seemed the window had to be up to get to everything?
(disconnect the window from regulator 1st to raise window?)

[1969GiPper]

On older vehicles it’s not uncommon for a wire in the harness to break inside the rubber conduit between the hinge pillar and the door. Over the years the wires in the conduit are being bent back and forth each time the door is opened and closed. Eventually one wire will break causing something inside the door not to work. Often when repairing that wire you will find other wires on the verge of breaking for the same reason. Not saying this is your problem but it is something to keep in mind.

[johnta1]

How would it be grounded normally?

Not real sure, but seems like it was through the bolts that connect it regulator? (like starter is grounded by bolts holding it on)

If it only has 2 wires at that plug it would be grounded through bolts. The door would also have to be grounded to the car chassis.

Try a jumper cable to the motor housing and to battery ground, then try 12 volt positive to the blue wire?

I also agree with 1969GiPper.

[johnta1]

Also, if you can get to the bolts holding the motor on, go ahead and take it off. There will be nothing keeping the window up (if it were up) so be careful around the pinch points of the regulator and glass.


Once off, should be easy to check if it works.
Also would be easy to see if anything is binding up on the regulator mechanisms.