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Hi,

I want to use the ECU to turn an oil cooler fan on and off on my air cooled VW Beetle. I am assuming that the fan control is triggered from the engine temp sensors which is not appropriate.

I have looked at using one of the AUX outputs, triggering from the oil temperature, but they need an on and off point, and I would not want the fan turned off until it is below the on point.

Any suggestions?

Thank you.

You still use the Aux outputs.

Set the on value to your switching temperature, off to the maximum.
The hysteresis is used to work out when to turn the fan off again.

So On at 50, Off at 500, Hysteresis 5 will turn the fan on at 50 degrees, and back off only when the temperature drops below 45.
It will also turn the fan off if the oil goes over 500C...

You can set the amount of hysteresis in the software yourself, so it will turn the fan on at say 90 deg and not turn off again until the temp has got down to say 80 if you set the hysteresis to 10 deg.

Thanks for the help.

I have wired the oil cooler in with a relay to be triggered by Aux4. With the temperatures and hysteresis set as described above. However, when trying to trigger the Aux4 output through the test function it does not work.
Using a continuity checker to check the ground, when I trigger the test I get a very short signal.
As I am using the Aux4 is there another setting that I need to change?

Thanks.

The test doesn't use the settings in the map, it's purely there to check the wiring.

The test also just turns the output on. However, there needs to be a load on the output for it to remain on, so a continuity checker across the output probably won't be enough.
We just use a small LED or lightbulb to provide a load.