5.0L Windor V8 Hilux EFI Conversion

EB-ED V8 Thermofan Control

This guide outlines the steps involved in controlling an electric thermofan via the Factory ECU in an EB-ED V8 Falcon, XR8, Fairlane or Fairmont. This guide does not apply to the I6 as the parameters to enable fan control are currently not known.

Tune changes to enable Thermofan control

The following changes are required in the bin to enable fan control. This applies for a 2DCA bin but should also apply to other bins:

  • Enable the flag “Electro Drive Fan Present”
  • Enable the flag “High Speed Fan Present”
  • Set the “High Speed Fan Normal On Temp” scaler to the temperature (in degreesF) that you want the fan to switch on. Stock is 242degF.
  • Set “High Speed Fan High Load On Temp” scaler to the temperature (in degreesF) that you want the fan to switch on under high load.       Stock is 234degF.
  • Set the hysteresis functions to the number of degrees you would like the temperatures to drop after the fans cycle on. Stock is 4degF.

J3 Chip Options

We can make all of the tune changes necessary to enable fans on your EB-ED V8 ECU and load them on a chip ready to install!  See our range of J3 Chips below.



Wiring up your fan

The EB-ED V8 ECUs are fitted with a single output for fan control (despite having dual speeds in the software – the hardware is missing for the low speed output).

  • ECU Pin 41 High Speed Fan Output – low side trigger (negative to enable fan). Wire this to the relay coil with the other side going to fuel pump switched positive (so the fans are only enabled when the engine is running).
  • ECU Pin 51 Low Speed Fan Output – The hardware to drive this output is missing from the EEC.

As the ECU only enables the non-functioning low speed output when the A/C is on, you will need to add a second trigger to the relay in order to enable the fan when the A/C clutch is on. Failure to do this will result in high system pressures when stationery and possible A/C compressor failure. The A/C clutch is positively triggered so a second relay will be required.


Thanks to Rick Merino for his guide on how to enable the fans on the A9L strategy.

Happy Tuning!

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