Cooling Fan Operation and Troubleshooting

Introduction

When troubleshooting cooling fan problems, confusion often arises because the fan circuit differs between early (early) and later 944s. Some wiring diagrams in circulation are of poor quality or outright incorrect, and even the factory drawings can be difficult to follow. The descriptions here are based on the factory electrical diagrams and practical troubleshooting experience.

Choose your car

The cooling-fan circuit differs by model year and A/C equipment. Pick the configuration that matches your car for the dedicated troubleshooting guide.

• Late cars (late, all Turbos) — two fans, fuses 10 & 15, dual-element thermofan switch.
• Early cars with A/C (early) — two fans, fuses 3 & 5, A/C relay.
• Early cars without A/C (early) — single fan, fuse 3.