Hi all,

Before I start, It was Rallycinq that done the job for me and all credits goes to him. Just writing this guide to help anyone wanting a fan override switch.

What you need are:

  • Relay
  • Relay Holder - Optional but it makes it look so much tidier
  • Thick and thin wires
  • Switch, i removed my rear wiper motor so I used that instead.

1 - Unplug the temp sensor on the side of the radiator:


2 - T the wire from the relay to the radiator plug:


See the red and black wire in the picture above; you need to T the black to black and red to the other wire on the plug. (You need to use the thickwire for this job)

3 - Find a suitable place to bolt the relay/relay holder; I have decided to bolt it right at the slam panel, as you can see in the picture:


The small black wire next to relay holder is the earth connecting from the relay to the chassis.

4 - Connect a wire from the relay to the switch (use a thin wire), in my case the rear wiper motor switch. In the 899 cinq, this is the blue wire as shown in the following picture, but you could just test it with a multimeter that you should get a 12v reading wire the wire once the car is in ignition position.


5 - I have used the rubber grommets under the passenger foot well to run the wire in, as you can see in the following picture:


Just test if it works when you started the car, but the switch should work when ignition is in position 1.

Hope this helps.

  • Thanks
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