My fan's wiring is complete! I've decided to run it off the ignition for right now, summer heat in stop and go traffic and all.. But I have one loose end.

The relay won't activate until this last wire gets a ground, so what ignition source would get a ground when active? Or I could rewire it to power side.. whatcha think?

 

i thought ground was always active. i just wired mine to come on when the car reaches a certain temp, via an adjustable thermostat, autozone $20

 

Ignition wires are positive, not ground. You would need to use a relay to invert the ignition ON signal if you needed a switched ground.

 

Ok I'll switch the coil wires for positive switch, now closest to the battery, what ignition 12v 30amp supportable source is there?

 

None... again you need to use a relay

 

so i need to use 2 relays?

Using aaroncakes wiring dagram from your FAQ with just the thermostat control except an ignition positive instead?

 

One relay

Aaron's drawings all call for a relay as well...Not sure what you are asking



OR

 

I've got his entire set up complete minus a temperature sensor..

I decided instead of running it off a TS, for now, I'd wire it to a 12v ignition source as close to the battery as possible. I heard about the "test pin". Thinking of going that route.

And I already have 1 relay wired in.

*edit*
And i ran the first wiring diagram.

 

You can't do the first drawing with ignition control. That is for battery power only. You didn't read that???

If you want ignition control you need to use the 2nd drawing. If you are not using a T-stat switch, then you need to just jumper the wires that normally would be connected to the T-stat switch.

 

damn, guess I have to do some rewiring once I get home.

 

You need to do a little more research on how cooling systems work. Running the fan constantly will not make the car run cooler and it will not help in summer heat. The engine's temp is controlled by the thermostat. It will not let the engine run cooler than it should, so running the fan constantly is pointless. All it does it add an unnecessary load to the electrical system and shorten the life of the fan. Do it right, get a thermoswitch so the fan only operates when it's actually needed.