power windows in a 1991 Fleetwood.

[QuirkyCadGuy]

Well my problem child is acting up again. Fix one thing and two break. The latest issue is my power windows in this 91 Fleetwood.  The front power windows will suddenly not go down. The rear windows work fine. All of the other switches in the driver's door work fine. The passenger side front window will not go down even using the switch in the passenger door. This all happened without warning. They were working great until they didn't work at all. Fuses and relays have all been checked. Has anyone had this issue before? Any suggestions would be appreciated.

[936CD69]

James, assuming the window lockout switch is not set to on, a quick read of the service manual suggests the most likely culprit is the master window switch on the drivers door. If you have the service manual, there are function tests to perform in section 8D cell 120 which don't require much more than a test light or DVOM.

HTH,

Craig

[QuirkyCadGuy]

The window lockout is in the off position.  I will test the master switch in the drivers door. Would a faulty master switch keep the passenger door switch from activating the passenger side power window?

[936CD69]

The grounds for all the motors go thru the master switch, so yes it could be at fault. Depending on whether you press up or down, the power is provided by either the master switch or the other door switches, but the ground flows back thru the master to facilitate reversing the motors.

[QuirkyCadGuy]

Well that makes sense. Thank you very much for the reply Craig.

[TJ Hopland]

Yes in the pre body control module era it was quite a maze of back in fourth in things like the window switches.  When the switches are 'off' they are still making contacts, when you turn them on its just a different combination of contacts.  When no switch is being pressed they actually are in a bypass sort of mode so that if only one switch gets activated that signal has to pass through the other switch to get to the motor.   Drivers door switch usually seems to be the issue because its used more often and often times since the switches physically point up in the armrest rain or snow lands on them and works its way inside and corrodes the contacts.   

[Walter Youshock]

Don't dismiss the possibility of water contamination in the motors themselves.  I've had more trouble with my '91 Brougham windows than any of the other 6 Cadillacs I've had.  I found a capacitor in the main motor connector to harness that shorted on one motor.  Jumping it keeps the motor working.

With BOTH fronts out, it could be a switch issue.  If you could jumper the rear switch leads to the front contacts, you might be able to get them to work.