power windows work .. how?

[firebird77clone]

Hiya. Having trouble with the power Windows in my 73 charger.

I expect the motors run by reversing the polarity, but I can't figure out the ground. I was expecting the ground to switch in, but it doesn't seem to. Neither does the motor go to ground.

Help?

[sunsetdart]

The motor being bolted to the metal inside the door is whats making the ground. I would remove the motor from the door and then test it.

[35WINDOW]

Remember,

there are four basic designs in Power Window Circuits:

-Negative Pulse
-Positive Pulse (with and without Relays)
-Voltage Reversal Rest at Ground
-Variable Voltage

I would first find your Relay(s) (if there are any) and trace out the wiring-what powers the Coils? What triggers the Coils? Does the Relay have an 87a Terminal? Is it bridged? And so on-

[firebird77clone]

Ok, lots of staring at the wiring diagram and here is what I've got:

BTW I hate wiring diagrams, I much prefer schematics.

Looks like the ground routes through the drivers side switch, which is missing. Thus, no ground.

Also looks like the motor is isolated from ground, so must operate be reversing polarity (switching both leads).

So, since the passenger side switch only switches one motor lead, bad switch on pass side.

[firebird77clone]

Ok. I have a new pass side switch. It connects the motor leads (normally closed) to the drivers side switch. the drivers side switch connects the two leads ( normally closed ) to ground.