Keith Roberts

76 D100 318. Where would be a good power source for the fan and fuel pump to run off of? What gauge wire for the pump? The main wire that's on the pump is small. I don't plan on using a relay. I will use a relay on the fan? Anybody have a good way to Wire these up?

TVLynn

Better off using a relay !!! esp mounting it in the rear as the pump pushes better than it pulls...

Iowan

Something like that.

RacerHog

Better to use a relay... I agree...

xaza

I agree with the smart guys before me that relays are good. Control circuits for relays draw minimal power and can be run with small wire. You will want to find a 12V signal from ignition to power relay solenoid for fuel pump. Fan can be done same way if you want it to shut off when the vehicle does. Connect supply power for relays to battery. You can wire relay solenoid from battery if you want it to run with key off. You can control it with a toggle switch, time delay relay(shuts fan off after ? minutes ignition off) or a temp sensor that shuts it down when temp drops below ? degrees. Times and temps are variable. Depending on the route you run wire and amps of motors wire size can vary. The size of wire on pump is not necessarily right wire to get power that far. This should help you determine wire sizes.
http://www.engineeringtoolbox.com/am...uge-d_730.html
or this
http://www.solar-wind.co.uk/cable-sizing-DC-cables.html

and don't forget a fuse as close to power source as possible, I have seen the terminals melted off a battery when the winch wires shorted with no inline fuse. (I'm still looking for a quality 500 amp fuse before it happens to me)