Sunroof Component Testing

Overview

This guide helps you test and troubleshoot the sunroof components on your Porsche 944 (16v engine variants). The sunroof system relies on several electrical parts—like the micro-switch, relays, limit switches, console switch, and motor—to open, close, and lock the sunroof. Testing these ensures your sunroof works smoothly, which is key for comfort and avoiding manual operation hassles.

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Tools Required

• Multimeter
• Jumpers/Test leads
• External 12 VDC voltage source (e.g., a 9V battery or car battery)
• Small flat-tip screwdriver
• Plastic spatula (optional for gentle prying)
• Phillips head screwdriver
• 10mm (3/8 inch) wrench (for general use, if needed)
• Soldering iron (for micro-switch replacement)

Parts Required

• Micro-switch (if replacement needed)- 944 613 111 00
• Main sunroof relay (if faulty)- 944 615 117 00
• Directional relay (if faulty)- 944 615 116 00
• Console switch (if faulty)- 944 613 531 00

Required Additional Procedures

Steps in these procedures are required to complete this process:

• Sunroof Operation, Troubleshooting, and Repair

Step-by-Step Procedure

Step 1: Test and Replace the Micro-Switch Between the Sun Visors

1. Release and remove the sunroof hatch. If it won’t move electrically, manually release the lifting arms. Follow this link to ensure this step – Sunroof Operation, Troubleshooting, and Repair – of the process is followed accurately.
2. Gently pry off the triangular flap between the sun visors using a small flat-tip screwdriver or plastic spatula. Be careful—clips can break easily.

3. Remove the Phillips screw holding the mount, then press the mount off the wind deflector bar.

4. Press the flap or micro-switch lever and listen for a click. No click? Test it electrically.

5. Lower the mount and connect a multimeter (set to ohms) across the micro-switch terminals. It should read infinite ohms (∞) when not pressed.
6. Press the lever—it should drop to less than 1 ohm. If it fails, unsolder the wires and replace it with a new micro-switch (944 613 111 00).

7. Check the sunroof hatch tab. If it’s bent and won’t trigger the switch, bend it upward slightly with the hatch installed until you hear a click.

Step 2: Test the Main Sunroof Relay

8. Disconnect the sunroof switch plug: Remove the storage pocket under the radio by pressing outward and pulling it out, then remove two Phillips screws.

9. Pull the ashtray up and out, then remove two more Phillips screws at the console’s back.

10. Lift the console insert (remove radio trim if needed) and release the switch plug’s four plastic tabs carefully with two small screwdrivers.

11. Turn the ignition to ACCESSORY and use a multimeter to check for 12 VDC at terminal 2 of the switch plug.

12. Turn the ignition ON. Check for 12 VDC at terminal 1, and ensure voltage at terminal 2 is gone.
13. If voltages are off, locate the main relay (G18 on the central electric panel) and remove it.
14. Check relay socket: ACCESSORY should show 12 VDC at terminal R; ON should show 12 VDC at terminals A and R. If voltages are correct but output fails, replace the relay (944 615 117 00).

Step 3: Test the Limit Switches

15. Find the limit switches above the sunroof motor (Limit Switch I = bottom, II = top, III = backup).
16. Use a multimeter (ohms) and test per this table for the 944’s late system:
17. LOCKED: I (1-4 <1 ohm), II (1-4 ∞), III (1-4 ∞)
18. OPEN: I (1-4 ∞), II (1-4 ∞), III (1-4 <1 ohm)
19. RELEASED: I (1-4 <1 ohm), II (1-4 <1 ohm), III (1-4 ∞)
20. If readings don’t match, replace the faulty switch (check wiring colors in the original article).

Step 4: Test the Console Switch

21. Remove the console switch plug as in Step 2 (8-10).
22. Test with a multimeter (ohms): Press BACK (A) for <1 ohm between 2-5 and 1-3; press FORWARD (B) for <1 ohm between 2-6 and 2-4.
23. If readings fail, release the switch’s tabs with a screwdriver and replace it (944 613 531 00).

Step 5: Test the Directional Relays

24. Remove both relays near the sunroof motor. Pry gently with a screwdriver if needed—watch terminal 87 (always live).

25. Test each relay: Check 30-87a (<1 ohm). Apply 12 VDC to 85 (+) and 86 (-)—it clicks, 30-87a should be ∞, 30-87 <1 ohm. Disconnect—it clicks, 30-87 should be ∞.
26. If a relay fails, replace it (944 615 116 00).
27. Check terminal block: 12 VDC at both 87s to ground, <1 ohm at 86 and 87a to ground. If off, check fuse #1 on the central electric panel.

Step 6: Test the Sunroof Motor

28. If all else passes but the motor won’t run, disconnect its plug and apply 12 VDC directly. No movement? Replace the motor.

Step 7: Test the Ignition Switch

29. Turn ignition to ACCESSORY—check 12 VDC at relay socket terminals A and R.
30. Turn to ON—check 12 VDC at terminal 15. If voltages fail, inspect the ignition switch or wiring.

Post Procedure Checklist

• Ensure the sunroof opens, closes, and locks smoothly.
• Check for unusual noises or resistance.
• Verify all electrical connections are secure.
• Test the micro-switch tab with the hatch installed—listen for the click.

Sources

• Clark’s Garage
• Pelican Parts
• Porsche 944 Workshop Manual, Volume 1
• Youtube