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Clark's Garage944 · 924 · 968 · Turbo

Thermofan Switch Replacement

Procedure for replacing the thermofan switch on the 944, including coolant drain, fan assembly removal, torque specs for plastic and brass thread bosses.

Difficulty: Moderate1 min readApplies to: 944 · 944 Turbo · 944S · 924S
Download factory PDF

Tools Needed

  • Floor jack
  • Jack stands
  • Metric socket set
  • 29 mm or 1-1/8" deep socket or combination wrench
  • Drain pan

Other Procedures Needed

  • COOL-02, Cooling System Draining, Filling, and Venting

Procedure

  1. Disconnect the negative terminal of the battery.
  2. Jack the car and place the front end on jack stands.
  3. Remove the belly pan.
  4. Drain approximately 2 litres (slightly more than 2 qts.) of coolant from the radiator by removing the drain plug at the bottom of the radiator on the driver's side. Reinstall the plug after the required amount has drained.
  5. Remove the fan assembly. Some owners have completed this job without removing the fan assembly by using a long extension and socket, but access is very limited.
  6. The thermofan switch is located above and to the left of the driver's side cooling fan.
  7. Disconnect the electrical connector from the switch.
  8. Using a 29 mm deep socket, remove the switch.

Note: Due to differences in manufacturing tolerances, a 1-1/8" deep socket may fit. However, due to the tight space, removing the switch with an open-end or box-end wrench is nearly impossible.

  1. Check the threads in the radiator to determine whether they are plastic or brass.
  2. Install the new switch, using a new washer.
  3. Torque the switch based on thread material:
    • Plastic threads: torque to 20 Nm
    • Brass threads: torque to 28 Nm
  4. Reconnect the electrical connector to the switch.
  5. Reinstall the fan assembly.
  6. Fill and vent the coolant system using the COOL-02 procedure.
Tags:thermofan switchcooling fantemperature switchreplacement

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