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

Symptom	Possible Cause	Checks
Window will not move	Blown fuse	If only one window is affected, the fuse is good. If neither window moves: Early 944 (pre-1985.5) — Fuse 8 (16A), Additional Fuse Panel. Late 944 (1985.5 and newer) — Fuse 4 (30A), Central Electric Panel.
Window will not move	Bad relay	If only one side is affected, the relay is good. To bypass: remove the relay and jumper terminals 30 and 87 — the ignition need not be on. On early 944s, the relay is on the lower left of the center console near the DME. On late 944s it is G7 on the Central Electric Panel.
Window will not move (one side)	Bad switch or bad wiring	The most common single-side cause. The passenger-side switches are wired in series through the driver's side switch. Try swapping a known-good switch (from the working side) into each switch position for the faulty side to isolate the problem.
Windows move slowly	Dragging window mechanism	Lubricate the tracks on the window mechanism. For door panel removal access, see BODY-11 (Door Panels — Removal and Installation).
Windows move slowly	Weak window motor	Check for correct voltage at the power window motor plug when the switch is operated. For door panel removal, see BODY-11.

---

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 below).

---

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: A switch confirmed non-operating was successfully restored by contact cleaning alone in many documented cases.