I've got a solenoid I'd like to use to replace my burnt out relay by way of a push button switch. It has three terminals, one that connected to power, one that connected to the starter, and one that came in from the interior. What I'm double checking is that the metal cylinder on the bottom of the solenoid is needed because it moves up and completes the main circuit, and whether or not the terminal that went to the interior should go to the button which goes to power.
In other words, I have a switch that's connected to power, and the third terminal. When I hit that switch, it energizes the coils which draw the big cylinder up and connects the other two terminals so the power goes to the glow plugs, correct?