i need instructions on how to wire a toggle switch to my coolant fans either primary or secondary.

if i rember correct their is a geen wire with a white strip on your fan realy you tap into that and ground it out through the switch. i belive that you can do both the green wires and ground out both of them to work keep both fans on

so tap into the grn and white wire going into the relay or coming out of the relay?

Welcome to TGO. The sticky at the top of the page may prove helpful. BTW, a search is always a good idea.

JamesC