you need the plugs that go onto the wiring loom? because i reckon i have a spare wiring loom laying around that i could cut them off?

Yep, that would work.
Could do a version, for you, with all three plugs so could work on either EF or EL fans.

so this meaning i wont need my relays or mechanical switch that i bought? also how much would it cost for that mate?

Cheers,
Brandon

What'd you actually do there Murray?

Splice into the factory resistive sender that feeds to the computer? Or you've used your own?

And hence some kind of circuit to work out what resistance decides which speed?

And an AC feed in too?

Cheers,
Tim

The first version I made used a dual temp switch which turned the fans on at half or full speed as well as to half speed when the aircon was used. Used four relays and some diodes.
Had that in for years.

I then had a request from several guys for the thermo fan setup.
Decided that the setup I had used was to difficult as the thermo housing needed to be removed to install an adapter (3/8 NPT to 14mm) for the dual thermo switch. The dual thermo switch price had gone up as well.
One of the vehicles was a Fairmont with climate so the method was not able to be implemented anyway.

So I designed a new version.
The controller I made is microprocessor controlled.
Reads the voltage on the sender to determine when to turn the fans on/off or at half speed or at full speed.
Also takes an input from the A/C clutch to run the fans when the A/C is on.
There is a circuit board in the grey case that has the microcontroller, interface circuits as well as the relays to control the fans.