Q:
A: If you want it run to a toggle switch, wire in a relay. You don't want all that draw to be going into the cab and through a switch. It will get better power directly from the battery through a relay. The thermo switch is the best way, so you don't have to remember to turn it on. However it is not required to have an electric fan at all. My 93 didnt come with one and has not over heated here in Oklahoma where it has been 105*..