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Fan / Temperature Switch

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Product Information
Product Information

Fan temperature switch by OE Match. This version has a 2-pin electrical connection and controls cooling fan operation according to coolant temperature.

Fits

  • Porsche 924 1976-85
  • Porsche 944 1982-85
  • Porsche 928 1978-86

Check fitment for your specific vehicle (model, year, engine) before ordering.

Diagram ref: 5

What This Product Does

The switch responds to coolant heat by changing the electrical state of the fan control circuit. This allows the cooling fan to operate when required, particularly while the vehicle is stationary or moving slowly and natural airflow through the radiator is limited.

Functions

  • Provides temperature-dependent switching for the electric cooling fan.
  • Controls fan activation as coolant temperature rises.
  • Allows the fan circuit to change state as the coolant cools.

Technical Details

  • Part reference: 823959481F.
  • Brand: OE Match.
  • Electrical connection: 2 pin.

Symptoms of Fault

  • The fan remains inactive despite rising coolant temperature.
  • Fan operation continues without the expected temperature-related shut-off.
  • Coolant temperature increases during slow-moving traffic or while stationary.
  • The fan starts inconsistently or activates later than expected.

These symptoms do not confirm switch failure on their own. Fan motors, relays, fuses, damaged wiring and poor terminal contact can produce similar behaviour.

Why Replacement Matters

A confirmed switch fault can interrupt temperature-dependent fan control. Replacing the defective component addresses the switching fault rather than leaving the fan permanently inactive or operating continuously. Check the surrounding electrical connections and cooling system at the same time, as a replacement switch will not resolve a separate motor, relay or coolant circulation problem.

FAQs

  • Does an inactive fan always mean the switch has failed?
    No. Diagnose the motor, electrical supply, fuse, relay and wiring before deciding which component needs replacement.
  • Why might the temperature rise mainly in traffic?
    With less airflow from vehicle movement, radiator cooling depends more heavily on the electric fan.
  • Can trapped air affect diagnosis?
    Yes. Air pockets can cause uneven coolant temperatures, so correct filling and bleeding are important when investigating cooling faults.
  • What should be checked before fitting?
    Compare the original reference, connector and vehicle application. Follow the model-specific installation procedure and check for leaks and correct fan operation afterwards.


Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

823959481F
823959481F
06031

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Special Order item
823959481F
Product Information
Product Information
Fan temperature switch
2 pin.

Fits:
Porsche 924 1976-85
Porsche 944 1982-85
Porsche 928 1978-86

Click 'Zoom in' for large parts diagram.
Diagram Ref No 5.

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

823959481F
823959481F
06031

The product you are viewing cross references to these numbers
DISPLAYING 1 to 2 (of 2 products)
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About Fan / Temperature Switch

Radiator Fan Temperature Switches – Precise Cooling Control for Porsche Engines

Radiator fan temperature switches play a vital role in your Porsche’s cooling system by controlling when the electric cooling fan turns on and off. These switches activate the fan at a specific temperature, helping regulate engine heat and prevent overheating — a critical function for both performance and reliability.

At Design911, we stock a wide range of genuine and manufacturer-quality radiator fan temperature switches suitable for the transaxle models, 911, Boxster, Cayman, Cayenne, Macan, and Panamera models. Each switch is built for precision, durability, and accurate temperature response, ensuring consistent cooling performance in every driving condition.

What Do Radiator Fan Temperature Switches Do?

The radiator fan temperature switch monitors coolant temperature and engages the cooling fan when heat levels rise beyond a set threshold. It:

  • Activates the radiator fan automatically to maintain safe engine temperature.
  • Prevents overheating during idling or low-speed driving.
  • Improves cooling system efficiency and engine longevity.
  • Ensures smooth operation by maintaining stable thermal balance.

This component is essential to preventing excessive heat build-up, especially in performance or stop-start conditions common to Porsche vehicles.

Why Do Radiator Fan Switches Fail?

Due to constant exposure to heat, coolant, and vibration, fan temperature switches can degrade over time. Common causes of failure include:

  • Thermal fatigue leading to inaccurate temperature readings.
  • Corrosion or oxidation on terminals reducing electrical contact.
  • Coolant contamination damaging internal sensors.
  • Cracked housings or seals leading to coolant leaks.
  • Age-related wear affecting switch sensitivity and reliability.

Typical symptoms include fans not activating, fans running constantly, or overheating at low speeds, all indicating a failing or inaccurate switch.

Why Replace a Faulty Radiator Fan Temperature Switch?

Replacing a worn or faulty temperature switch ensures proper cooling fan control and prevents overheating damage to your Porsche’s engine.

Benefits of replacement include:

  • Reliable fan activation at the correct temperature.
  • Stable engine operating conditions under all loads.
  • Prevention of overheating and related engine wear.
  • Long-lasting performance with manufacturer-quality materials.

All switches in our range are made with temperature-calibrated sensors and durable housings, ensuring precise response, corrosion resistance, and consistent performance across a wide temperature range.

1. What does a radiator fan temperature switch do in a Porsche?
The radiator fan temperature switch monitors coolant temperature and turns the cooling fan on when it gets too hot. It helps prevent overheating and ensures your Porsche’s engine maintains an optimal operating temperature for performance and efficiency.

2. What are the symptoms of a bad radiator fan switch?
Common signs include fans not activating, fans running continuously, engine overheating, or erratic fan operation. If you notice inconsistent cooling performance, the temperature switch may be worn or faulty.

3. Can I replace a radiator fan temperature switch myself?
Yes — many Porsche owners can replace the switch with basic tools and mechanical knowledge. However, since it involves draining coolant and sealing connections, it’s best performed by a qualified technician to ensure proper installation and no leaks.

4. How often should the radiator fan temperature switch be replaced?
Most switches last between 60,000 and 100,000 miles, depending on driving conditions and coolant quality. It’s best to inspect the switch during cooling system servicing or when replacing the radiator or thermostat.

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