Electric Window Troubleshooting

Introduction

When electric windows stop working, isolating the cause can be tricky. This procedure walks through the diagnosis systematically.

Tools

• Test meter (voltmeter/ohmmeter)
• Trim removal tool (if door panel must be removed)
• Phillips head screwdriver (if door panel must be removed)

Power window troubleshooter

Use the decision tree above to find the likely cause, then read the matching section below. A key clue is whether one window is dead or both: a single dead window points at a switch or its wiring, while both windows dead points at the shared fuse or relay.

Blown fuse

If only one window is affected, the fuse is good. If neither window moves, check the power-window fuse: early cars (early) — Fuse 8 (16 A) on the Auxiliary Fuse Panel; late cars (1985.5 and newer) — Fuse 4 (30 A) on the Central Electric Panel.

Bad relay

If only one side is affected, the relay is good. To bypass it, remove the relay and jumper terminals 30 and 87 — the ignition need not be on. On early cars the relay is on the lower left of the center console near the DME; on late cars it is G7 on the Central Electric Panel.

Bad switch or wiring, one side

The most common single-side cause. The passenger-side switches are wired in series through the driver's-side switch, so a passenger-window fault can originate on either side. Swap a known-good switch from the working side into each position on the faulty side to isolate the problem, then run the Window Switch Test.

Slow movement — dragging mechanism or motor

If the window moves but is slow, the mechanism is usually dragging — lubricate the tracks on the window mechanism (door-panel removal: see BODY-11, Door Panels — Removal and Installation). If lubrication does not help, check for correct voltage at the power-window motor plug when the switch is operated; low or no voltage with a good switch points to the motor.

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Window Switch Test

1. Remove the window switch from the door panel. There are four tabs (two on top, two on bottom) that must be released. Use a small flat-tip screwdriver under two tabs simultaneously to avoid breaking them.

2. Turn the ignition switch to ON.

3. Using a voltmeter, check the switch plug for approximately 12 VDC from terminal 4 (RD/GN) to ground and terminal 5 (RD/BL) to ground. Correct readings confirm the power supply and wiring to the switch is good.

4. Using an ohmmeter, check the switch contacts:

   a. Switch depressed in the open (down) direction: Resistance from terminals 1 to 4 and from terminals 2 to 3 should each be < 1 Ω. b. Switch depressed in the close (up) direction: Resistance from terminals 1 to 3 and from terminals 2 to 5 should each be < 1 Ω.

5. If any reading is out of specification, the switch is bad. Options are replacement or cleaning the contacts (see Window Switch Repair below).

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Window Switch Repair

Introduction

Most window switch failures result from dirty contacts. Disassembling and cleaning the switch usually restores correct operation. Switches that are physically worn or do not move smoothly may require replacement.

Procedure

1. The terminal block on the back of the switch is held by four tabs (two per side) that fit into detents in the switch body. Insert a small flat-tip screwdriver into the side of the terminal block to release the tabs. Hold the back of the switch facing up while doing this — the internals will fall out when the block is removed.
2. Remove the switch internals and inspect the contacts. High-resistance readings on the switch test typically correspond to visibly dirty contacts.
3. Clean the switch contacts and reassemble.
4. After reassembly, verify smooth mechanical operation and re-test per the Window Switch Test section.

Note: The switch documented in the original procedure was a non-operating switch that was restored by cleaning the contacts alone.