Wiring relays I put together to run the mark 8 fan. 10 relays 1 70 amps and 1 80 amps, 2 fuse breakers for high and low speed, 1 Derale adjustable fan temp control. The low speed fan kicks in at 185 if the temp go's pass that to 195 I have switch in side when I turn it on it kick's of the low speed relay when the high speed relay kicks in.