Any suggestions? My passenger side window stopped rolling up a couple days ago. Couldn't raise it with the drivers window switch or the passenger switch. The indicated to me that the problem was the motor, not the switch. Well, I replaced the motor ($114-OUCH) and still can't raise the window. I think I need to see a wiring diagram to troubleshoot. Any body have one???
When I get a vehicle in the shop with a complaint that one window does not operate, the first thing I do for a simple test is to turn on the dome lamp and watch it with the engine not running. If the light dims when operating the switch in both directions, the motor is lockedup or regulator binding. I always test the new motor before installing by simply plugging it in to the pigtail connector and operating the switch to ensure it runs both directions. If the dome lamp fails to dim in one or both directions then you have a circuit problem or bad switch. One thing people often make a mistake of is to try the passenger switch and fail to realize the window lock switch is on, disabling the passenger switches. So make sure if you have a window lock switch that it isnt locking out the other switches. You can completely diagnose most systems with a test light or multimeter with little need for an EVTM. Also if you install the motor without ensuring it is seated correctly in the regulator the new motor could be in a bind and not operate.
I have had a number of F150 with bad switches so that is a good possibility. Sometimes you can tell by using a test lamp and testing the passenger switch and see if you get a voltage feed from one terminal operating the switch both directions. The switch is supposed to change from a positive feed to a ground on each wire depending on direction... IE, if the test lamp illuminates in the up position on a given pin, then it should be ground in the down position. If it illuminates operating the switch both directions then the switch is bad. Basically the same holds true with the driver switch, but if there is a lockout switch it could also create similar effect. There is also a possibility of a broken wire in the area of the door opening inside the boot.
Although it is possible to find an open in the motor itself, it would be very rare.
Other common mistakes.. Opps forgot to plug in the motor... opps forgot to plug in both switches to test. (one switch out leaves an open circuit)
Last edited by HomerWinzlow; 08-09-2003 at 08:31 AM.
Thanks for the great reply! Got very confused last night when using my multitester as both sides of the switch show 12V+ when "up" switch is pressed, but motor doesn't operate. Motor does operate in down position only (same as the one I removed. Oops). Neither the driver side switch or the passenger side will roll the window up.
Since voltage on both sides is +12V on UP operation, can I assume switch is bad? I don't want to throw any more money at this unless I know the switch is bad.
Mattdad1, did you replace the passenger side switch or the driver switch? I know this sounds odd but the driver switch provides the power inputs for the passenger switch. Sometimes when the driver switch is bad, it prevents the passenger switch from working as well. Its all too common to replace the wrong switch, or even for both to be bad. This occurs because one will be bad and go un-noticed for sometime because it is seldom used, and is only realized when the other finally goes bad.
Other than that, the only other thing it can be is a broken wire. They are commonly broken inside the rubber boot between the door and the cab, from opening and closing over and over untill the wire or wires break.