If i takle my own loom...

ping · Posted: Wed Apr 22, 2015 10:45 pm Post subject:

Ok, I think I need to set it up so I run two fans from just two relays, one relay running both fans at low speed and one relay running both at high speed?

Kai · Posted: Thu Apr 23, 2015 6:49 am Post subject:

The standard Subaru WRX has 2 X DUAL speed fans.

The fan connector plugs are wired as :

Slow speed +12v
Fast speed +12v
Earth 0v

Use two relays to provide power to each speed on the fans. Provide a earth point for each fan.

Allow the ecu to control the relays powering the fans. The ecu will provide an earth to the relay solenoid so provide +12v to the other side of the relay.

I'll say it again, page 10 of the manual clearly shows this.
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ping · Posted: Thu Apr 23, 2015 7:00 am Post subject:

Cheers Kai I did look at page 10 when you first mentioned it but I was a bit confused as to how mine were actually wired up. I think it's cot something to do with being an aircon model. I'm going to change the wiring on them now to run off just the two relays.

ping · Posted: Thu Apr 23, 2015 7:04 am Post subject:

Looking again the diagram on page 10 only shows single speed fans. Is it ok to take the output from relay one and split it so it does both fans slow speed and then the output for relay two split to do both fans high speed?

Kai · Posted: Thu Apr 23, 2015 9:45 pm Post subject:

Yeah exactly that. Like a daisy chain

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ping · Posted: Thu Apr 23, 2015 10:07 pm Post subject:

Cool didn't know if it was too much load on the relays.

Kai · Posted: Fri Apr 24, 2015 5:41 am Post subject:

Can't remember but I think mine are fused at 20amps. Easy for a 30 amp relay.
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ping · Posted: Thu Jul 30, 2015 2:54 pm Post subject:

So after a while away from scooby wiring im nearly back on it, I've done the fan wiring harness and tested away from the ecu harness. Now I am looking at the alternator wiring. I take it the 3 thick white wires join up together and just go to the + terminal on the alternator? (why are there 2 wires with ring terminals and not just 1?)
And how do i wire up the small wire from the alternator, does it just join to the charge light wire on my van or do i need a diode?

Wilfred · Darth Admin Joined: 13 Nov 2013 Posts: 366

small wire from the alternator:

the light in your dashboard gets 12v when ignition is turned on. with the engine not yet started, the alternator is the earth and your alternator light lights up. Now if you start the engine, the alternator changes from a ground into a positive 12v signal, which it generates. Now your light has 12v at both wires, which means no current so the light goes off.

That is how it works.

You need to apply 12v to an alternator before it will start generating electricity. this is the 12v from your alternator light. Without this wire, your alternator will not start charging or at least not properly.

Don't know why there is two wires, have seen it more often. but never figured out why. Maybe they split at the other ends, which is easier this way?
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