DIY Network

Repairing a Faulty Power Window A stuck power window can be fixed easily and requires relatively few tools. From "Car Care & Repair" episode CCR-122

Power windows are a great convenience, but their disadvantage is that, should one of the electrical components fail, the window glass is stuck either in the up or down position. Fortunately, this problem can be remedied fairly easily, and requires relatively few tools or materials. It does require partial disassembly of the door on the side of the faulty window. It's a good idea to have your vehicle's service manual handy in case there are any special considerations or unique parts for your particular vehicle. In our demonstration, after diagnosing the problem we replaced the power-window motor on the passenger side of a 2000 model Ford Taurus.

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	For safety and to prevent damage, disconnect the vehicle's negative battery cable before beginning any project that involves electrical re-wiring.
	Figure A
	Figure B
	Figure C
	Figure D
	Figure E
	Figure F
	Figure G
	Figure H
	Figure I
	Figure J
	Figure K
	Figure L
	Figure M
	Figure N
	Media Click this image to download a video of the complete program segment showing this project.

Materials:

multimeter
replacement motor (if necessary)
trim-removing tool (pry tool)
screwdriver
nut driver
socket wrench

Safety alert : Since this project requires disconnecting and reconnecting some electrical wiring, disconnect the vehicle's negative battery cable as a safety measure before beginning work. The battery will need to be temporarily reconnected during the diagnostic portions of the project.

1. Once the negative battery cable is disconnected, the first step is to remove the interior door panel. This will require that you first remove any detachable trim-pieces from the door-latch assembly. In our case, we removed a small trim plate from the door-handle assembly using a pry tool. Use caution not to damage any of the trim pieces.

2. With the trim piece out of the way, begin removing the retaining screws that hold the interior door-panel in place (figure A).

3. Gently detach and lift off the interior door-panel and carefully set it aside. Aside from the screws, the door is held in place by some plastic retaining brackets. Gently pry and rock the panel to loosen it and work it free from the brackets, using caution not to break any of the brackets (figure B). Be careful not to scratch or damage the panel as they are expensive to replace.

4. With the interior door-panel removed, disconnect the wiring harness for the power door-lock (figure C) as well as that for the power window (figure D).

5. With the wiring harness disconnected, the power supply to the power window can be tested using a multimeter (figure E). Among other things, a multimeter can measure and display the amount of current being supplied to a particular electrical component such as an electrical motor or a switch. Its digital or analog (needle indicator) readout displays the amount of voltage flowing through. In this way, you can test a power source, and check to see whether an electrical component is receiving the proper amount of power. In our demonstration, our meter was equipped with alligator clips on the positive and negative sensors. We made makeshift needle-probes by using a straightened paperclip clamped in each alligator clip (figure F). After temporarily reconnecting the battery, we tested to make certain that the proper amount of power (around 12 volts) was being supplied to the switch that controls the power window. The test confirmed that the switch was receiving the proper amount of voltage (11.90 volts), and thus ruled out that as the source of the problem.

6. Multimeters can also be used to test continuity of electrical current in the switch itself (figure G). Continuity simply means that electrical current is able to flow continuously through a particular component or span of electrical wiring. When it's engaged in the "on" position, a properly working switch should allow current to flow through. The multimeter used in our demonstration utilizes a continuity feature that provides an audible signal when the positive and negative probes are touched together or when the probes come into contact with either end of an unbroken electrical current. Using the continuity feature (setting the meter to "ohms"), and connecting a probe to each pole of the switch, an audible tone indicates that the switch is working properly. Our test indicated that the switch was fine. Though not shown in the demonstration, we also used the multimeter to test the vehicle battery to make certain that it was good, and tested the fuse that regulates the power window.

7. Since the multimeter testing eliminated the power source, fuse and switch as the source of the problem, the only two possibilities left are the wiring that leads to the power-window motor and the motor itself. To gain access to those components, the front stereo-speaker was removed (figure H) and the moisture barrier on the door panel was peeled back (figure I).

8. Disconnect the power supply leading from the switch to the motor (figure J) and, with the switch reconnected, check for proper voltage (figure K). Since that test indicated that the power line was functional, the only possibility left is a bad motor.

9. To remove the motor, remove the retaining bolts from the door panel using a socket wrench (figure L). When removing the bolts, use caution when the last bolt is removed and hold onto the motor so that it doesn't fall and damage the glass. With the bolts removed, the motor can be taken out of the door panel (figure M).

10. Connect the replacement motor test it before installing it in the door panel. In our demonstration, with all electrical components connected and the ignition key on, the motor could be engaged using the power-window switch (figure N).

11. After testing, install the new motor in the door panel using the original bolts, then reverse the steps to reinstall all components:
    • Reinstall the wiring harness, switch, moisture barrier, and stereo speaker;
      
    • Reconnect the power door-lock switch and power window switch;
      
    • Remount the interior door-panel;
      
    • Replace the trim pieces.

Note: Keep in mind that the passenger-side window can be controlled by a switch on the driver side as well as the one on the passenger side. For a thorough diagnostic check, both switches need to be tested.

RESOURCES :

Auto Repair for Dummies
Author: Deanna Sclar
ISBN: 0764550896

Some vehicles provided by Ted Russell Ford

Ted Russell Ford
8551 Kingston Pike
Knoxville, TN 37919
Phone: 865-693-7611
Web site: www.tedrussell.com