Electric fan setups

[Mux213]

Ivan,

I would put the thermoswitch on the ignition like you suggest but I would actually put the fan directly on the battery,not through the main engine relais. Just put a fuse inbetween just in case you're fan motor brakes. Your relais will cut power to it when off anyways.

The reason is very simple. What you could do now is add a delay timer to the circuit. Something that causes the fan to run for another minute or so after the ignition is turned off. Especially with a fan mounted between the radiator and the engine is one that will keep blowing air past your engine after you've switched off. I've heard its better for your engine as the cooling stops when you turn off the ignition but there is still alot of heat inside your engine that can't get away.

Also you wont stress the engine relais