When I got my 99 with 80k miles, both power windows didn't work from either the drivers or passenger side switches. Power locks, memory seats, heat all ok. Now that I've sorted all the other larger issues with the car, I'm tackling the small stuff.
Here's what I've done so far:
-Removed drivers door panel
-Disconnected wire harness to drivers power window motor
-Used a multi-meter to check if drivers window switch is sending power to motor. Tested up and down on switch. Confirmed 12volts up and down. Switch seems to tests ok. Assumed motor is bad
-Ordered new power window motor
-Installed new motor, still not working.
-Disconnected window motor harness, used alligator clips to test window motor with a spare battery. Window moves up and down perfectly and smoothly.
-Again test switch and express down module with meter and harness to motor disconnected, all seems ok. I get up/down voltage, and hear relay clicks from module. Now I'm confused.
-Reconnect wire harness to motor, test, nothing. No clicks from express module, nothing.
-Use meter to test up/down on switch while harness is connected to motor, I get low up/down voltage.
Seems odd. Seems as when you connect the harness to the motor, you get no voltage from switch, and no clicks from express module. I repeat this testing multiple times, and I consistently get 12v up/down from switch, and hear relay clicking from express down module when harness is not connected to motor.
For reference, I test the removed stock drivers motor, and it tests ok.
What could it be? Bad express module, bad switch?
Weird one.