Need some help diagnosing my Z. The passenger window stopped working. I have power to the window motor connector, up and down, when using the passenger switch. There is no power to the connector when using the driver's switch. I have bench tested the motor and it works. Now when I connect the motor and attempt to operate via passenger switch, the motor won't work. My next guess is that it has something to do with the driver's switch.

I think this topic will get more attention on the "General 67-02 F-Body Tech" forum, rather than "Car Audio and Electronics", which tends to focus on "gadgets". I'll move the thread there for you.

Shoebox has some good info on the motors.....

Power Window Motor

" My next guess is that it has something to do with the driver's switch."

You are correct in that guess. All power for the passenger side window switch goes through the driver side switch for the passenger side window. It sounds like there is an intermittent contact in the driver side switch.

The answer you seek is called:

The Express Down Module



This is what provides the power from the driver's side to the passenger's side switch. Through a bad design by GM (Imagine that. Their engineering standards are crap), the express down module will fail resulting in you being able to operate the passenger's side window from the passenger's side door and not the driver's side.

Great news: The Express Down Module is no longer available from either GM or aftermarket. Your only choice is to get it in a junkyard or on Ebay.

Have fun!!!!!

The Express Down Module is easy to eliminate. Remove it and jumper the connector pin E (gray wire) to pin D (brown wire) .

Has anyone else bypassed this module with the mod Gary said?

The express down module should have nothing to do with the passenger window. The wiring for the passenger window does not go through it. Your passenger window will work even with the express down module removed. Blaming the GM engineers for a bad design was a bit premature.

The driver's side mounted passenger switch and connections have to be good for the passenger side switch to work. That much is true.

And, yes it works to bypass the module like Gary said (though that won't fix your problem).

Ok. Thank you for the clarification. I'm so far narrowing down to the window motors needing replacement than I'll check back in. Thanks to your site I'll be able to do it haha