could you go a little more in depth, I have idea what I am doing when it comes to electronics. It sounds easy until I try it maybe a step by step. and what will I need besides the 12volt switch :3question: :help:
Two types of circuit, parallel and series
Parallel is when the electricity has two paths to follow, it can go thru either the thermal switch and turn the fan on or thru the switch your adding to turn the fan on.
Series is when the power has on part to follow, if you added a switch in series you would have to turn on your switch and the thermal switch would have to be in the on position for the fan to run
I don't think you'll need to unplug the radiator, you just need splice the red/white wire.
In the picture #14 and #15 are in series, the red added switch is parallel to #15.