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.
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
- Disconnect the negative terminal of the battery.
- Jack the car and place the front end on jack stands.
- Remove the belly pan.
- 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.
- 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.
- The thermofan switch is located above and to the left of the driver's side cooling fan.
- Disconnect the electrical connector from the switch.
- 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.
- Check the threads in the radiator to determine whether they are plastic or brass.
- Install the new switch, using a new washer.
- Torque the switch based on thread material:
- Plastic threads: torque to 20 Nm
- Brass threads: torque to 28 Nm
- Reconnect the electrical connector to the switch.
- Reinstall the fan assembly.
- Fill and vent the coolant system using the COOL-02 procedure.