Electrical Q's

[johntramp]

right?

So I wire that to run through a 12v relay to the fan?

Cheers

[sergei]

yep, make sure that control side of the relay is grounded through this switch (more ASCII art):

````12V
``````┬
``````├───────┐
``┌──┴──┐`````│
``│`relay`│-------\
``└──┬──┘`````│
`````│`````````│
``┌──┴──┐ `┌──┴──┐
``│t/swtch│``│`FAN``│
``└──┬──┘ `└──┬──┘
`````╧`````````╧
(GND)V`````````V

[johntramp]

oh I see, so the thermoswitch will ground when it wants the fan to be on?

[sergei]

yep

[johntramp]

does the fuel circuit relay work similar to this?

[sergei]

I think FC output is 12V so you will have to connect other way arround (relay grounded, while powered by FC)...

[johntramp]

that thermostat switch has 3 Ohms resistance to ground, when the engine is cold. That to me sounds far too low...

[sergei]

Oh, it is inverse to normal switch (On when cold, Off when fan needs to be switched on) the thing is it would draw only 100mA max because it will "power" just a relay, if you are not using stock relay, you will have to use the contacts wich gets disconected when relay is powered.

[johntramp]

ok cheers, ill see what i can do.

[johntramp]

Does it matter what sort of relay I have? As I would guess that it up to the relay to decide when to switch over.

This relay I have here which I hope to use is;

RL- 020
TOYOTA 90987-04002
12V 5P

(last on page http://autolider.com.tw/acc%20parts/electrical%20%20parts/relays/OTHER%20RLY-2.htm)

[johntramp]

I just checked the FC output, and it is 2Ohms to ground when the engine is running and then goes up to 18Ohms when the engine stops. There is no voltage out of it at all... so I guess that needs a relay similar to the fan aswell.

[johntramp]

Would running the lead from the coil to the distributor alongside the loom through the firewall be a bad idea due to induced currents in the loom? If so, is there an easy way to insulate the lead so I am able to run them together?

Cheers

[sergei]

put it in silicone hose, while loom in earthed metallic braid/foil.

[johntramp]

ok cool, where would be the best place to pick up that kinda stuff?
cheers