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ecu signal to fan relay?

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Someone mentioned in one of the recent overheating threads that they had used a wire from the ecu to trip a relay for their own electric cooling fan. I just happen to have a reversible aftermarket fan from another car and would like to use it as my primary fan - to replace the mechanical.

 

Ea82, A/C so I have the secondary fan too.

 

Now, I would rather avoid a manual switch and don't go seriously off road (I'm not worried about immersing a running fan, if that happens I have much bigger issues) but the price of the universal thermostatic fan controllers is ridiculous.

 

It sounded like, if I connected to some signal from the ecu, it could activate a relay and be a fan controller.

 

Looking at the pinout from my ecu I'm not able to tell which lead that would be, I have the terminal numbers and the voltage listing, but not necessarily the function...

Just wire the existing thermoswitch to control your relay ground and run both fans from the new relay. No ECU hacking required and I don't beleive there are any ECU outputs that would be useful.... in fact I don't think there are really any ECU outputs other than diagnostics on the EA82's.

 

GD

  • Author
Just wire the existing thermoswitch to control your relay ground and run both fans from the new relay. No ECU hacking required and I don't beleive there are any ECU outputs that would be useful.... in fact I don't think there are really any ECU outputs other than diagnostics on the EA82's.

 

GD

 

that sounds awesome, and very simple, I guess now I must test my thermoswitch to see if it is working correctly - Gloyale set me straight on how to check that -

 

30 amp relay okay?

 

thanks so much for clearing that up for me, I can do that with stuff I have on hand :banana:

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