Assuming you are talking about a 12V aftermarket or donor electric radiator cooling fan, that switch is NOT suitable for an electric fan.
Red leader to Blue leader....Negatory on the switchatory.
Using a dash on/off switch is the wrong way to go. Using a two speed switch will be a disaster for the fan motor if low speed is used. The voltage reducers you have been reading about are to reduce 12V to 6V to operate existing 6V components. I have asked you this already in a previous post but you did not confirm. A radiator cooling fan? NOT a cab, blow in your face, cooling fan, right? A 12V fan, right?
The proper way is a thermostatically controlled electronic fan control switch, operating the fan thru a relay.
Also, what is the reason for an electric fan? What motor do you have? 235? Is it overheating? There is a fix that moves the fan up for some motors, available from Pre68Dave.
AD motors should not need an E-Fan if all is well. If A/C is added, maybe.
I believe this discussion should be on a new thread. It's kind of a general rule not to morph.
