how do i properly run high amp 12v electric switch

[IamMeYouAreYou]

Here's what i got going. I'm converting my truck from a clutch driven fan to 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

[DeltaP]

I would control the fans through a relay circuit keeping the high amperage wiring out of the cab and from behind the dashboard! That hot switch you were getting could have been a sign of impending disaster. Make sure the relay is capable of handling the amperage necessary to run the 2 fans. You'll need a temp control to manage the on/off demand for the fans operation. Don't count on trying to manage them manually.

[Mastercarpentry]

Ditto on the relay. DC wiring loses power rapidly over longer distances. And high-amp switches (if you can find them) ain't cheap- that's why the factory's use relays. Be sure to fuse it, and to fuse the wiring to the switch or more than the radiator may end up hotter than you wanted

Boneyard trick: When at the pick-and-pull, grab a couple relays that will accept the regular sized tab connectors for the wiring and toss them in the trunk Look for the ones marked for headlights, these are usually 30A. These are good for diagnostics or temporary repairs. You can replace a lower-rated relay with a higher-rated one (but not the reverse) as the relay coils all draw minimal current- it's the contacts that are amperage rated.

Phil