I put in a manual switch a while back.. it is wired from the fans into a switch then back from the switch through a inline fuse and to the battery.. I am burning up switches like crazy.. how do i put a relay in.. would it just go right before the fuse on the side going to the battery?

 

Too much current to safely pass through a switch. There are fan switch schematics on my Tech Page that use the factory relays.