Spal Fan Wiring Question

[jlevie]

There should be an accessory fuse block clipped to the forward side of the main fuse box. One position in that block is switched power and the other is always hot. Use the switched side for the relay coil. Run a wire to the main power point on the right side of the firewall. Be sure to use the main power connection (big cable), not the smaller wire connection that serves the injection electronics.

Yes the black/green wire.

What size SPAL did you get? Here in the south I think that the fan needs to be 1800cfm or greater. I use a 2300cfm SPAL.

One more think. Don't even think about using the "through the radiator" mounts for the fan. They can (and usually will) eat a hole in the radiator core.

[Frog]

Thanks for the info! 88c side you mean the black and green wire?

Also, where should I connect the orange wire 'ignition switched' to? What is a good location?

[jlevie]

In the drawing above you are supplying power to the relay coil on #86. The relay will close when #85 is grounded through the thermo switch. If you also tie one side of a switch to #85 and the other to ground the relay will close when the switch closes. With an 80/88C thermo switch, I'd suggest that you use the 88C side, even though it is a bit higher than would be ideal.

[Frog]

I bought thermo switch 61-31-8-361-787 which is 80/88c.

How do I connect the switch? #85 to ground? Isn't the fan already grounded? Shouldn't it connect to battery +?

[jlevie]

If you use the stock aux switch, which isn't a good idea. You must tie the low and high switch wires together. If you use just the low temp switch, if the temperature rises high enough to activate the high temp switch, the low switch opens. That would turn off the fan when it is most needed. If you tie the wires together, there might be a problem with the aux fan control. I've not looked at the wiring diagrams to see.

The standard aux fan operates at 91C & 99C. The low side is really too high and you should use a switch that operates a few degrees above the thermostat rating. For the stock 80C thermostat a thermo switch rated for 82-83C is what you want. BavAuto and other places have that thermo switch.

To add a manual control you'd run a wire from #85 above to a toggle switch and from the switch to ground.

[Frog]

I am trying to wire up my Spal fan, I was thinking of connecting it this way:



But I also would like a switch in the cabin that I could flip to force/override the fan ON.

How would I do that?