Troubleshooting – Electrical (including Instruments)

Overview

This guide helps you identify and fix common electrical and instrument problems on your Porsche 944 S / S2 with the 16v engine. It covers issues like wipers or gauges not working, dim dash lights, or a dead battery, offering simple steps to get your car back in shape. Fixing these yourself can save time and keep your S / S2 running smoothly.

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

Tools Required

• Jumper wire
• Wire brush
• Emery cloth or mildly abrasive material
• Dielectric grease
• Flathead screwdriver (for bulb removal)
• Phillips screwdriver (for light assembly)

Parts Required

• Replacement turn signal bulb (if filament is broken) – 944 631 211 00
• Flasher relay (if needed) – 944 615 115 00

Required Additional Procedures

Steps in these procedures are required to complete this process:

• Instrument Panel Light
• Rear Hatch Defroster Troubleshooting and Repair
• Excessive Battery Discharge Rate
• Sensors and Gauges

Step-by-Step Procedure

Step 1: Fix Wipers, Blower Motor, Reverse Lights, Cooling Fans, Power Windows, and Power Mirrors Not Working

1. Locate Relay X on the terminal board under the hood of your Porsche 944 S / S2 (specific to the 16v engine model).
2. Remove Relay X carefully by pulling it straight out.
3. Insert a jumper wire across the primary contact slots where Relay X was plugged in.
4. Test the wipers, blower motor, reverse lights, cooling fans, power windows, and mirrors to see if they work with the jumper in place.
5. If they work, replace Relay X with a new one – no part number is specified for Relay X, so consult your Porsche dealer for the correct S / S2 relay compatible with the 16v engine.

Step 2: Brighten Dim Dash Lights

6. Check the instrument panel lights for flaking reflective coating, burned-out bulbs, or low-wattage bulbs.
7. Follow this link to ensure this step – Instrument Panel Light – of the process is followed accurately.

Step 3: Repair Rear Defroster Not Working

8. Inspect the rear defroster for a damaged lug, broken grid, or power loss.
9. Follow this link to ensure this step – Rear Hatch Defroster Troubleshooting and Repair – of the process is followed accurately.

Step 4: Address Battery Going Dead Quickly

10. Look for a possible ground fault in the electrical system causing excessive battery drain.
11. Follow this link to ensure this step – Excessive Battery Discharge Rate – of the process is followed accurately.

Step 5: Fix Blown Fuse #11

12. Check the glove compartment light wiring for a short. The red wire may rub against the metal brace above it, blowing fuse #11.
13. Bend the red wire downward away from the brace to prevent contact, or swap the red and brown wire positions on the light assembly.
14. Replace fuse #11 with a new one rated for the S / S2 – no specific part number is provided, so match the original fuse rating (typically 15A).

Step 6: Troubleshoot Instrument Panel Gauge Not Working

15. Investigate if the gauge, its sensor, or wiring is faulty.
16. Follow this link to ensure this step – Sensors and Gauges – of the process is followed accurately.

Step 7: Correct Turn Signal Blinking Too Fast on One Side

17. Identify which side blinks faster than normal.
18. Remove the turn signal bulbs on that side using a flathead screwdriver to access the housing.
19. Clean the bulb sockets with a wire brush to remove dirt or corrosion.
20. Clean the bulb contacts with emery cloth or a similar abrasive material.
21. Apply a thin layer of dielectric grease to the bulb contacts.
22. Reinstall the bulbs and test the turn signals.

Step 8: Fix Turn Signal That Lights Up But Doesn’t Blink

23. Check if the issue affects one side or both sides.
24. If one side doesn’t blink, remove the bulbs on that side and inspect for a broken filament.
25. Replace any bad bulb with a new one – 944 631 211 00.
26. If both sides light up but don’t blink, replace the flasher relay – 944 615 115 00 – located under the dash near the fuse box.
27. Test the turn signals after replacement.

Post Procedure Checklist

• Verify wipers, blower motor, reverse lights, cooling fans, power windows, and mirrors operate normally.
• Ensure dash lights are bright and even.
• Confirm the rear defroster heats the rear hatch glass.
• Check that the battery holds a charge after sitting for 5 miles (8 km) of driving.
• Test fuse #11 by turning on the glove compartment light and checking it stays on without blowing.
• Confirm all instrument gauges respond correctly to engine conditions.
• Ensure turn signals blink at a normal rate on both sides.

Sources

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