What is your question?

 

I have had a Link ECU fitted and set up in my H22 Gen 4, now giving 245BHP.

We have one issue to overcome, control of the coolant fan.

With the AC turned on, both fans work as they should.

But with the AC off, the main cooling fan does not engage.
We suspect this may be a ground issue as the ECU is using a simulated ground as opposed to an actual ground.

Looking at the wiring diagram, there is a control box in the system, but I cant find any info on it.

I have a UK 1996 model, so I have two coolant sensors on the block , seems not all models have the sensor on the thermostat housing that I have.

Any help advice welcome, also should the fan come on after ignition off while the engine is cooling??? my car has spent the last 2 years being restored, uprated so I cant recall.

 

The control box is a timer, keeps the fan running key off if the temp is high. Pull off the connector for the main fan switch (at the thermostat housing, rear of block) and put a paper clip in to jumper the two terminals- the fan should come on.