[DAVID GAGNARD]

I converted my old Ford alternator to a one wire type,not anywhere near my car,but best I remember, the alternator output is connected to the battery side of the starter solenoid,not 100% sure but maybe 8 gauge wire,I know it's pretty good size......on my other computer I have a wire size chart I can post but that will not be until Friday before I can get to it and my car to verify......

If my memory is right(???), big gauge wire from the alternator side of the starter solenoid to the relay, then from the relay to the fan,again big gauge wire.....I have a toggle switch under the lip of the dash to turn on the electric fan,it is wired manually only....just the way I wanted it....... I tied into the toggle switch with a "standard" size hot wire from under the dash as it only carries 12 volts to engage the relay,so no big wire is needed..........it works and works well and has been wired this way for at least 15 years.......

Wish I had the wire chart handy, it shows the size of the wire and the length and how much amperage that size wire,that length carry safely handle,very informative........
the other thing is anything pulling the amount of amps electric fans pull needs to be wire on a relay and not just straight wires/switches, they can't handle the amperage/heat for very long before they melt and/or short out...

BTW: the only time I need to use the electric fan is in city driving, anything over 35 mph or so on the road, I have enough air flow thru the radiator to keep the engine temp at 180.........

David