25. Here’s the radiator/fan combo installed in the car. We set the controller to come on at 180 degrees. The green wire you see runs from the controller and was spliced into the air conditioning compressor’s clutch circuit. This turns the electric fan on automatically any time the compressor is on. The results have been impressive to say the least. Now, the coolant temp on the high stays in the 170- to 180-degree range, even with the A/C cranking in the tropical summer heat.