Lower Temperature Auxiliary Fan Switch – E36

The E36 have an engine driven clutch fan attached to the water pump and an electric auxiliary fan in front of the radiator. The clutch fan is often removed to save weight, free up horsepower and to clean up the engine bay.

Although the electric auxiliary fan is primarily used with the A/C, it will also turn on if the coolant temperature in the radiator gets hot enough via the double temperature switch on the right side of the radiator.

The OEM 6-cyl double temperature switch turns the auxiliary electric fan on low speed at 91C (196F) and high speed at 99C (210F). This alternative lower temperature double switch operates at 80C (176F) and 88C (190F) respectively and is recommended to be used when removing the clutch fan.

Additionally, the stock electric auxiliary fan is often replaced with an aftermarket electric fan, such as a SPAL 16″ Medium Profile Puller Fan mounted on the back side of the radiator. This lower temperature double switch can be used to automatically turn an aftermarket fan on depending on how you wire it*.

A new sealing washer will be provided with this switch.

Notes:

* – The stock auxiliary fan wiring has a single power source to both a Low Speed Relay and High Speed Relay, each controlled by this double temperature switch (as well as the AC and/or DME). When we rework stock E36 harnesses for a SPAL fan, we will only keep the High Speed Relay, but have it switched on via the lower temperature value of this switch. An additional Manual Override Switch or Digital Output Control can also be wired in when doing this too.

 – The connector used on this switch varies depending on your production date. Up to 09/1995 has larger round pins while From 09/1995 have smaller square pins. Make sure to select the correct version.

 – The stock late model connector may need the keyway cut off to plug into this switch. This can easily be done with flush cut pliers or a razor blade.