The way mine is set up the switch does not activate the solenoid, it kills the ground to it. It has a spring on it. When the ignition is on 12 volts goes to solenoid and holds plunger back...when it hits the rpm the switch is set at it cuts the ground to thev relay and the spring pushes the shifter fwd. Mine is not a window switch though...it is just an MSD RPM switch