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#1040695 - 06/24/16 02:31 AM Power Window diagnosis  
Joined: Oct 2003
Posts: 1,063
RoadWarrior Offline
15+ Year
RoadWarrior  Offline
15+ Year

Joined: Oct 2003
Posts: 1,063
Mechanicsburg, Pa
Hey guys, Here's a write up on how to diagnosis your power windows. I give a couple of examples, but the general steps for diagnosing the system remains about the same, whether one window only works in one direction, from one switch, or from both switches, or doesn't work at all from one switch, the most common problem found is normally going to be the contacts for the ground side of the circuit, either in the master switch, or the passenger door switch.

On a side note, GM and a few other manufacturer's use this same window set-up FOREVER, 80's-2008-ish which means you can use this same knowledge to possibly fix your DD as well, pretty much anything GM up into the mid 2000's use this same basic setup, certain feature's were added through the years, like passenger windows lock-out, auto up and down features, light switches, which are just a few more wires, and the auto features are built into the switches, but still the same window control functions. Today at work, i had an 05-ish saturn Ion with a power window issue and it was still this same set-up and even used the same blue and brown wires for the driver's door motor. It wasn't until rather recent years that they switch to bus/module control systems.

Basic system operation:
The power window system uses reversible motors and window switches that supply both power and ground to change direction of operation of the window. This means that when a switch is pressed in the "up" position, that one wire contact in the switch is connected to power, and the other ground, and then when pressed "down" those same wires switch polarity. this is achieved through the contacts in the switch by being in constant contact with the ground tab, and in the passenger door switch in contact with the driver's door wires and are only disconnected from ground when that pin is given power.

also, the passenger side window motor and switch receive ground through the master switch contacts. which means that while the master switch is at rest, and you press either up or down on the passenger side switch, power is applied at the passenger side switch, but the path to ground travels from the passenger side switch, back through the crossover wires in the dash harness, through the contacts in the driver's door switch, and to ground.

Removing window switches for test:

there's two ways to remove the switches,

you can either:
remove the upper door panel by removing the pull strap end covers and screws, and pulling up and out the upper door panel (you may have to remove the door panel armrest, and loosen the lower door panel screws to do this as well depending on how tight everything is.)


you can try to release the clips holding the switches into the door panel.

First thing to note is that there is a metal ring around the opening in the door panel for the switch. The clips on either side of the switch snap behind this. So in order to pop the switch out you'll have to compress the switch and pull inwards towards the car at the same time. if you look on either the left or right side (not the top or bottom) of the switch, while prying under the switch bezel slightly, you should be able to see the metal ring. right behind that on the side closest to the door will be the part of the retaining clip that you have to compress so you can pop the switch out. once you get one side's clip past the metal ring you should be able to work the switch out of the panel.

with this information in mind, it's now easier to diagnose the window switches.

Wiring color chart:

Driver's door Master switch:

Pink wire at pin F-Ignition hot power from fuse block 30amp circuit breaker.
Black wire at pin A-Ground
Brown wire at pin B-Driver's window down power wire (ground for up)
Blue wire at pin C-Driver's window up power wire (ground for down)
Tan wire at pin D-Passenger window down power wire (ground for up)
Blue/white stripe at pin E-Passenger window up power wire (ground for down)

Passenger door window switch:

Pink wire at pin A-Ignition hot power from 30amp circuit breaker
Tan wire at pin B-wire from driver's door switch down power/up ground
Blue wire at pin C- wire to motor (up power/down ground)
Brown wire at pin D-wire to motor (down Power/Up ground)
Blue/white stripe wire at pin E- wire from driver's door switch up power/down ground.

-testing for power, either use a DVOM, or a test light connected to a known good ground

-testing for ground, either use a DVOM, or a test light connected to power

now, with this knowledge, let's apply it to an example:

let's say that everything with you windows work, except the passenger side window won't go up from the passenger door switch, but it works in both directions from the driver's side switch.

the first step would for any situation, would be to check for power, since the window works in this situation works going down and not up, we know we at least have power to the switch on the pink wire, since the window will go down, but we should check the Blue wire at pin C on the passenger switch will pressing the button for "up" to verify it's putting power out to the motor.

If the blue wire has power, the next thing to check would be to also verify the brown wire from the motor to the switch is getting power from the motor in the "up" position, which if the motor works in the down position, you should see power at the switch.

Now here is where the first possible cause could be. Check to see while holding the switch in the "up" position, if you have power on the Tan wire at Pin B, if you have no power here, but you have continuity to ground on the Tan wire, that would mean that contacts in the passenger window switch for ground for the "up" position, which is the Tan wire and the brown, are not touching while the switch is in the up position. And if Ground is present on the Tan Wire, that means the contacts in the master switch are good. to verify this, jump the tan and brown wire together with either a jumper wire, paper clip, or even a pair of needle nose pliers, and now press the passenger window switch to "up" the window should now go up, verifying the loss of connection in the passenger switch, at this point you can skip down to "repairing switches"

IF there was power on the Tan wire of the passenger switch while pressing up, that means that the contacts in the passenger switch are working, so now you have to move over to the driver's door master switch.

first thing to verify over here would be that power is making it to the master switch on the Tan wire at pin D, while pressing "up" on the passenger side switch. Once this is verified, then Ground the Tan wire at the master switch, then press up on the passenger side switch, the window will now go up, this means that the contacts in the Neutral position of the master switch is not in connection to ground.

another issues would be that the passenger window doesn't work in either direction from the driver's switch, but works from the passenger door switch. The easiest way to start with this would be to remove the passenger door switch, and jump the Brown wire to the tan wire, and then the blue wire to the blue/with white stripe wire, then operate the driver's master switch controls for the passenger window and the window should now work, indicating the contacts in the neutral position of the passenger switch are bad.

If it still doesn't work with the passenger window bypassed, then your failure is in the master switch, either the ground on power side, which then you can determine by testing the master switch for both proper power and ground on the designated wires, while in each position.

Repair or Replace switches.

you have a choice to either repair the switches, or replace them.

the first thing about replacing switches is that there does seem to be a difference in quality. These switches work for a TON of GM cars, so that means that everyone makes replacements, you can even find them in the Dorman HELP section/catalog, which these are cheap and normally available, but do have a tendency to fail/or even not function in all positions when new.

I personally have one's From Summit racing from a Company called Electric-Life which work absolutely great, they even came with new connector pigtails.

So if you plan to just replace the switches, just be cautious, or at least aware that the cheaper ones, may not work out well for you, or you may need to go through 2 or 3 until you get a good one, or even take apart the new switch, and fix it, and then put it in.

It is possible to repair the window switches. Normally what causes them to fail, is tarnish/wear and the slight "burning" of the contacts/points inside the switch. the easier switch to learn how to fix/repair would be the passenger side switch, since there's less parts, but the theory applies to both switches. with the switch removed and unplugged, flip it upside down so the wire tabs are pointing up. with a small screwdriver gently pry between the chrome bezel and the black/blue/white plastic of the actual switch to release the switch from the bezel, you may have to gently pry both sides a little, one at a time to get it to pop out of the bezel. and depending on the switch make, it may actually come apart at this stage, so be gentle. once out of bezel flip the switch back over so the tabs are facing down, and gently release the tabs and pull the top off the switch.

Now the contacts and the problems are exposed. you'll see to "V" kinda shaped strips opposite each other!!! remember which way they face!!! now to see if the there is any corrosion or burning that's messing up the power flow, remove one of the strips, and clean off the small little contacts points that touch all three points, repeat for the other remaining strips and contacts, and then reinstall cover, and bezel, and then test operation before reinstalling into door.

WHEW!!! that was fun. I hope that helps whomever may need it. thanks guys.

88 SS, 355 owned since '03
#1040773 - 06/25/16 03:00 PM Re: Power Window diagnosis [Re: RoadWarrior]  
Joined: Sep 2011
Posts: 1,542
LXXXIV SS  Offline

Joined: Sep 2011
Posts: 1,542
Lower Peninsula, Michigan
Bookmarked and saved. Thank you!

#1040870 - 06/29/16 12:22 AM Re: Power Window diagnosis [Re: RoadWarrior]  
Joined: Jul 2005
Posts: 2,671
gmachinz Offline
10+ Year
gmachinz  Offline
10+ Year

Joined: Jul 2005
Posts: 2,671
Des Moines, Iowa
This is all basically correct except-the wires don't actually switch polarity-the motors are reverse polarity style but a more accurate description is to say all the window switch leads except the pink ones are normally grounded at rest. Moving the button one way or the other simply switches that one wire from ground to power. The 3rd gen fbodies are actually a switching polarity style switch-the switches are normally open at rest-moving the button one way or the other puts ground and power to the two window motor leads.

It's a small detail granted but it matters if you want to add late model express features to the system.


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