Porsche 924 & Early 944 Electric Window Fault Finding Guide

Porsche 924 & Early 944 Electric Window Fault Finding Guide

Porsche 924 & Early 944 Electric Window Fault Finding Guide

One of the more unusual electrical systems on the early Porsche 924 and pre-1986 Porsche 944 is the electric window circuit. Unlike many modern cars, the window switches work together as part of the circuit, which means a fault with one switch can affect the operation of the other window.

If you've got a window that refuses to move, here's a quick checklist before condemning the motor.

1. Check the Fuse

Start with the basics.

Check the window fuse and confirm it hasn't blown. If the fuse continues to fail, investigate for wiring faults before fitting another.

2. Check Both Window Switches

This catches a lot of owners out.

The early Porsche 924 and 944 window switches rely on each other to complete the circuit. A faulty passenger switch can stop the driver's window from operating and vice versa.

If one window isn't working:

  • Try operating both switches.

  • Swap the switches left to right if possible.

  • Look for signs of overheating or melted terminals.

A failed switch is often the culprit.

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Porsche window switch

3. Listen for Motor Noise

Press the switch and listen carefully.

If you hear the motor:

The motor is receiving power.

Likely causes include:

  • Window mechanism seized

  • Regulator fault

  • Glass binding in the runners

If you hear nothing:

Continue down the checklist.

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4. Check for Power at the Motor

Remove the door card and access the window motor.

Using a multimeter, check whether power is reaching the motor when the switch is pressed.

Power Present

The motor is likely faulty.

No Power Present

The fault is usually in:

  • Window switches

  • Wiring

  • Connectors

  • Earth connections

5. Inspect the Door Wiring

Repeated opening and closing of the door can fatigue wiring over time.

Pay particular attention to:

  • Wiring between the door and body

  • Corroded connectors

  • Loose terminals

6. Test the Motor Directly

If you're still unsure, disconnect the motor and apply power directly from a suitable 12V source.

If the motor runs, the fault lies elsewhere in the circuit.

If it doesn't, the motor is likely due for replacement.

Common Cause on Early Cars

The most common fault we see on early 924 and pre-1986 944 models is a failed window switch.

Because the switches interact with each other as part of the circuit, diagnosing the fault can sometimes be confusing. Many perfectly good motors have been replaced only to discover the problem was actually a faulty switch.

Need Parts?

At Stuttgart Spares we stock:

  • Early Porsche 924 window switches

  • Early Porsche 944 window switches

  • Brown and black switch variants

  • Replacement window motors

  • A range of electrical and interior components for transaxle Porsche models

If you're unsure which switch your car requires, get in touch and we'll be happy to help.

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