anyone installed a temperature switch for their tranny fluid temp? I have a project vehicle that has a remote cooler and fan combination that i would like to turn on when the tranny reaches like 200F then turn off somewhere below 180F.

 

I would use the switch that is sold for the aux engine fan. Hypertech and others make this switch. Wire the relay on the fan to use a ground trigger and the sensor will provide the ground for the relay when the temps are reached.