How to control Radiator Fan via Link
 

Hey there.
I've read the installation guide on the FM manual,
But does anyone know how I can use the Link to control the Fan using a relay??

Vvvvvvvvvvvvvvvvvvvvvvv

M2cupcar
wow! that was really useful! Really appreciate the help :)

Hope u didn't have to draw the whole diagram out

already had it- just swapped a ground for the "link"

Roger!
Thanks a million!

So the Link switches ground to activate the fan?

Just asking b/c the stocker switches +12V.

Yes. The 90-93 stock cooling fan goes to ground on the thermoswitch (that's why it's only one wire). The a/c fan goes +12v.

Yah I looked into it, and also saw Shiv's post. If the Link doesn't change the setpoint--and just relies on the oem thermoswitch--then there's really no need to run the fan through the Link.

But since the Link already runs the stock fan relay, there's no need to do anything.

In the most recent FM 1.6 software you can control the "on" point for the fan by running the OE thermoswitch lead to the LINK. Otherwise the LINK has no control over the fan "on". That's not the case with the 1.8s, as the LINK comes with fan control enabled- because the factory ecu controls the fan (unlike the 1.6).

As copied from the FM install guide.

'Fan Control (optional)
In 1.6L Miatas, the primary cooling fan is controlled by the temperature sensor on top of the thermostat housing. If the car is fitted with A/C, the second fan is controlled by the A/C system, turning on when the A/C is turned on. We have recommended connecting the A/C fan in parallel
with the power wires on the primary fan in the past to provide more cooling for turbocharged cars. When the primary fan turns on, both fans will turn on. This is still recommended, but we also have an alternative.
Terminal 1L will go to ground when the temperature of the coolant rises higher than the set point in Z9. This terminal can be used to trigger a relay that can run the fans in numerous different ways. For example, the primary fan can stay connected to the temperature sensor
(which closes at 97*C) and the A/C could be controlled by Z9 in the ECU. Or, both fans could be wired in parallel and controlled from the ECU. To use this feature a wire will need to be run from terminal 1L, through the firewall, to a relay in the engine bay.'

Hmm. am i reading you right? so i can just tap the OE thermoswitch and save myself the trouble of running a new relay?

Yes IF you're not running a high load fan. I'm running a single 16" spal that runs ~22amps at startup so it's a must to run the heavy gauge wires and relay per the diagram. The thermoswitch lead runs to the OE relay, so you're swapping the LINK trigger to ground for the thermoswitch- terminal 1L in the harness connects to the relay end of the thermoswitch lead. OR you can just take your 1L wire and tie it in to the thermoswitch lead so that the thermoswitch circuit remains intact and can serve as a backup (for whatever reason).

I'm planning to leave the main fan on the thermoswitch, and then use the link to switch the A/C fan (my car has no A/C) on and off.

So I'll have no choice but to use a relay.

Ok.I've read the post a couple of times and am still quite lost. Must be the lack of coffee and sleep.
What do I need to do to run the stock relay/thermoswitch?
If not, I assume a wire from 1L to a relay, as mentioned in your first reply would work, with the necessary New additional hardware and wires

Hi, i have a 1990, 1.6. After i installed a reroute kit i have tried to get my Link to control the fan without any success.

The first thing i did was to remove the green and black wire from the oe fan relay and replace it with a wire from 1L on the link. I didn't work.
I then tried to use a separate relay using m2supercar´s diagram. That didn't work either. But if i ground the 1L wire on a separate spot (not trough Link) the fan works with both oe fan relay and the separate relay. It seems like my Link won't ground trough 1L, or am i doing something wrong?