Electric fan bypass switch

[84cutspreme]

Spal recommends using a relay to turn on their fans. I don't think they care if you use a relay to turn on/off the relay that turns on their fans.

The ground wire being switched is the thermal switch ground, not the fan ground.

I have dual relays powering the fans. sending unit is ground to activate relays. I am adding in a switch to trigger sending unit if I want fans on when temp sender has not been activated. 12volt ignition powers relays all the time and power to fans has 30amp fuse inline. fans are grounded to the chassis. all as per Spal