Okay, got a 35amp switch and I quickly see that my electric fan blows that out so I knew a solenoid would get the job done and have many other uses but I'm clueless on how they work. I assume like a big relay? It's a four post Ford solenoid and I would guess the two larger ones get 12v with the one getting it only when 12v is supplied to either one of the smaller two? Is this correct, could you tell me how they work or do you have a diagram? THANKS A LOT!!!