1970s 1973 CoupeDeville

[34837]

Suddenly the passenger side window control does not work. Window controls on driver side operate all windows fine. Not sure where to start, or if involves disassembling door which Id rather not do at this time. Perhaps spraying electrical contact spray in mechanism? Thanks, 34837

[James Landi]

Clearly an electrical issue, and more specifically  the wires associated in the passenger door or the passenger door switch is the first place to start diagnostics. If you know how to use a multimeter, that could prove helpful in focusing your attention on the issue.  I'd start by investigating the wires at the door hinge.  Depending on how your model was designed, some models have wires that are protected by a simple rubber boot, and thus the wires are constantly flexed each time the door is opened. I've encountered breaks in wires at that location that, after some manipulation of that door boot were obvious. Roll down the passenger window to mid level, then go to the passenger side, and while holding the window switch in the up or down position, try opening and shutting the door. Does the window motor engage? Try manipulating the boot.. If the window motor comes to life, you know it's wire bending fatigue at that hinge area.
The other issue might have to do with switches.  Does your model have a window motor defeat switch on the driver's door.  Does it have an emergency switch that engages the window motors when the ignition is off? In such cases power to your passenger switch may be contingent on another switch (or two switches) at the drivers door. In such cases, removing the driver's door switch so you can use a multimeter on the switch plug will provide hard evidence of the failure. With one lead of your multimeter connect to a good clean ground, and the other testing the pins on the passenger switch, if you get NO voltage on any of the four connections, then there's no power and you have to diagnose wiring at possible failure points.  Depending (again) on your model, an emergency ignition off momentary switch or a driver's door switch only could be your issue.  Hope this helps. 

[TJ Hopland]

I would have to pull up a 73 manual which I don't happen to have in front of me but typically windows wiring is a little more complex than you would expect.  Because of the multiple controls when the switches are at rest they are are not just off they are connecting the other switch so the 'working' switch could be the the one with the problem in that when its not in use its not making the connection that allows the other one to work. 

And ya don't forget about that lock switch.  Its not something that is often used so its easy to forget about and may get crusty from lack of use.