Id like to start by saying im grad to have switched from chevy to ford. Not because of the trucks but because of this forum. Ive made so many posts on automotive forums and others like it to get little to no replys but here I get great and fast advice. Any way here's what i got going. I'm converting my 1996 f250xl 351 windsor 4x4 w/plow and utility box from a clutch driven fan to a bid single or dual electric fan setup. Ive ran fans to switches in the past on clunkers but to switch would always get hot. Im eventually going to get one of those adjustable cooling fan control units but for now I need the money else ware in the truck so im going to run it to a switch for now. I want to do it right this time so im not sure if i should run a heavier gauge positive lead into the cab to a high amp switch (2 fans so they will be like 8+amps per fan I think) or can i run the positive from the fan to a straight 12v and just run the ground to the switch (if so will this cause a draw that drains the battery) or is there a relay or something i can grab of a junkyard car(many to choose from at the local bone yard) that i can splice is line somewhere because i think what a relay does is ((a lower voltage circuit can be used to trip a relay, which will control a separate circuit that requires a higher voltage or amperage)) need some advice asap. thanks

 

You absolutely want to use a relay to switch the fan. Keep the higher amperage leads as short as you can and out under the hood.
I like the idea of having B+ to the relay coil all the time and switching the ground. If the wire from the relay to the switch shorts, the fan will come on instead of blowing a fuse/burning the wire.

Why not just put the swap on hold until you can afford the fan controller? I know I don't like doing things twice.