Sunroof Operation, Troubleshooting, and Repair – 2.5L NA

Overview

This procedure covers the operation, troubleshooting, and repair of the sunroof on a Porsche 944 (2.5L NA engine) for pre-1985.5 (1983–1985.5) and 1985.5 onwards (1986–1988) models. The sunroof is raised and lowered by lifting arms driven by a motor and flexible cables. Pre-1985.5 models use a gearbox with short drive cables, while 1985.5 onwards models use plastic gears. This guide explains how to operate the sunroof, remove and install it, manually operate it, adjust the motor slip clutch, and troubleshoot common issues to ensure smooth functionality.

Pink and blue text represent links to additional resources, tools, parts, and partner websites.

Tools Required

• Phillips screwdriver
• 10mm (3/8 inch) wrench
• 21mm (13/16 inch) socket or spark plug socket
• Torque wrench (capable of 5–15 Nm or 4–11 ft-lbs)
• Ammeter (for pre-1985.5 models)
• Manual operating tool (pre-1985.5 models, included with vehicle)

Parts Required

• Sunroof motor fuse (25A, 944 615 107 00) – pre-1985.5 models
• Sunroof motor fuse (25A, 944 615 108 00) – 1985.5 onwards models
• Plastic sunroof gears (1985.5 onwards, 944 564 113 00) – if stripped
• Sunroof gearbox (pre-1985.5, 944 564 111 00) – if damaged
• Loctite 270 (high-strength threadlocker)

Required Additional Procedures

Steps in these procedures are required to complete this process:

• Sunroof Component Testing
• Plastic Sunroof Gear Replacement

Step-by-Step Procedure

Step 1: Operating the Sunroof

1. (Pre-85.5) Turn the ignition switch to the “ON” position. Push the sunroof console switch back (“A” direction) to open the sunroof or forward (“B” direction) to close it.

2. (85.5 Onwards) Turn the ignition switch to the “ON” position (position 2). Push the sunroof console switch back (up arrow) to open the sunroof or forward (down arrow) to close it.

Step 2: Removing the Sunroof

3. (Pre-85.5) Turn the ignition switch to the “OFF” position. Depress the sunroof switch in the back direction (“A”) to retract the lifting arms.
4. (85.5 Onwards) Turn the ignition switch to the “ACCESSORY” position (1). Depress the sunroof switch in the back direction (up arrow) to retract the lifting arms.
5. Release the two latches at the front of the sunroof.

6. From inside the car, push up on the back of the sunroof and slide it off the wind deflector and front guides.

Step 3: Installing the Sunroof

7. Slide the sunroof hatch onto the wind deflector guides until it seats at the front of the sunroof opening.

8. Lower the back of the sunroof into the opening; it should sit flush with the roof.
9. Engage the front latches.
10. (Pre-85.5) Turn the ignition switch to the “OFF” position. Depress the sunroof switch forward (“B”) to raise the lifting arms to the locked position.
11. (85.5 Onwards) Turn the ignition switch to the “ACCESSORY” position (1). Depress the sunroof switch forward (down arrow) to raise the lifting arms to the locked position.

Step 4: Manual Sunroof Operation

12. Unclip the carpet on the driver’s side of the rear hatch to access the sunroof motor and cable drive assembly.
13. (Pre-85.5) Locate the manual operating tool below and to the left of the motor, attached by two wing nuts. Unscrew the wing nuts to remove the tool.
14. (Pre-85.5) Remove the cap over the adjusting screw below and to the right of the motor. Use the tool to remove the adjusting screw.

15. (Pre-85.5) Insert the tapered end of the tool into the threaded sleeve where the screw was removed. Turn counterclockwise to close the sunroof or clockwise to open it.

16. (Pre-85.5) After manual operation, reinstall the adjusting screw and proceed to Step 5 for slip clutch adjustment.
17. (85.5 Onwards) Remove the plastic cover (if present) over the motor assembly and the cap over the slip clutch adjusting screw, located below and to the right of the motor.

18. (85.5 Onwards) Use a 21mm (13/16 inch) socket on the large nut behind the lock nut to manually operate the sunroof. Turn clockwise to close or counterclockwise to open.

Step 5: Adjusting the Sunroof Motor Slip Clutch

19. (Pre-85.5) Remove fuse 9 from the auxiliary fuse panel and connect an ammeter across the fuse block terminals.

20. (Pre-85.5) Thread the adjusting screw into the slip clutch until the lock nut contacts the mounting surface, then tighten slightly.
21. (Pre-85.5) Turn the ignition on and operate the sunroof switch to move the sunroof to the fully open position. If the micro-switch between the sun visors stops the motor, manually press the micro-switch to continue operation.
22. (Pre-85.5) Check the motor current when the motor reaches the fully open position. Adjust the screw until the current is 12–14 amps, loosening the lock nut if necessary.
23. (Pre-85.5) Tighten the lock nut against the mounting surface and apply Loctite 270 to the screw threads at the lock nut.
24. (Pre-85.5) Disconnect the ammeter and reinstall the 25A fuse (944 615 107 00).
25. (85.5 Onwards) Open the sunroof halfway to prevent damage to the plastic gears (944 564 113 00).
26. (85.5 Onwards) Using a 21mm socket and torque wrench, turn the hexagonal nut on the slip clutch. Check the torque six times at 60-degree intervals during one full rotation. The clutch should slip at 5–5.5 Nm (3.7–4.1 ft-lbs) to protect the gears.
27. (85.5 Onwards) If adjustment is needed, loosen the lock nut, adjust the torque by turning the adjusting nut (tighten to increase, loosen to decrease), then apply Loctite 270 and tighten the lock nut to 15 Nm (11 ft-lbs).

Step 6: Troubleshooting Sunroof Issues

28. If the sunroof motor doesn’t operate, check the fuses: (Pre-85.5) Fuse 6 and 8 (main panel), Fuse 9 (auxiliary panel); (85.5 Onwards) Fuse 1 (motor), Fuse 8 (relay). Replace with 25A fuses (944 615 107 00 or 944 615 108 00) if blown.
29. Test the micro-switch between the sun visors, limit switches, main sunroof relay, console switch, directional relays, and motor. Follow this link to ensure this step – Sunroof Component Testing – is followed accurately.
30. If the lifting arms retract but won’t raise to the locked position, test the console switch, micro-switch, Limit Switch 2, and Directional Relay 1. Follow this link to ensure this step – Sunroof Component Testing – is followed accurately.
31. If the arms move but won’t retract for removal, test the main relay, console switch, and Limit Switch 1. Follow this link to ensure this step – Sunroof Component Testing – is followed accurately.
32. If the sunroof raises but won’t lower, test the console switch, Limit Switch 1, and Directional Relay 2. Follow this link to ensure this step – Sunroof Component Testing – is followed accurately.
33. If the sunroof lowers but won’t raise, test the micro-switch and console switch. Follow this link to ensure this step – Sunroof Component Testing – is followed accurately.
34. If the sunroof raises automatically when the car moves, adjust or replace Limit Switch 2. Follow this link to ensure this step – Sunroof Component Testing – is followed accurately.
35. If the motor turns but the sunroof doesn’t move, check the slip clutch torque. If too low, adjust as in Step 5. If the plastic gears (85.5 onwards) or gearbox (pre-85.5) are damaged, replace them. Follow this link to ensure this step – Plastic Sunroof Gear Replacement – is followed accurately.
36. If the arms raise unevenly, inspect the drive cable or plastic gears. Replace as needed. Follow this link to ensure this step – Plastic Sunroof Gear Replacement – is followed accurately.

Post Procedure Checklist

• Verify the sunroof opens and closes smoothly in the “ON” position (both models).
• Confirm the lifting arms retract and lock correctly in the “OFF” (pre-85.5) or “ACCESSORY” (85.5 onwards) position.
• Check that the sunroof sits flush with the roof when closed and latches securely.
• Ensure no unusual noises occur during operation, indicating loose or damaged components.
• Test manual operation (if performed) to confirm ease of movement.
• Verify slip clutch torque settings: 12–14 amps (pre-85.5) or 5–5.5 Nm (3.7–4.1 ft-lbs) (85.5 onwards).
• Inspect for stripped plastic gears (944 564 113 00) or damaged gearbox (944 564 111 00) if issues persist.

Sources

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