They are triggered by a temp sensor as well, but when they are wired to direct battery voltage the temp sensor allows the fans to keep running even after the car is shut down, until the temp reaches the adjustable shutoff temp. Thats why I ran it to a keyed power source so that the fans wouldn't run after shut down. It keeps the fans completely automatic and only allows them to run if the car is running and the temp is above the turn on temp. I just dont like the amount of current thats running through that keyed connection point.

I suppose I could switch it over to a constant 12v which would allow the fans to run after shutoff, and just live with it if I have to. But I would prefer to keep it a keyed 12v.