hey steve let me ask...the fan switch it activates based on a voltage input?yes?no? like the iat and other sensors could nt you have just put an inline resistor and tricked the fan switch into thinking it were hotter than it really was?

 

Nope, it is a mechanical switch. Think of it as a simple mechanical relay that closes at a cetrain temperature. The circuit is open when below the pre-set temp and closed to ground when at or above that temp.

This ground path then closes another relay which supplies power to the fans.