Magnum Neutral Safety Switch, effect idle? and wiring?
I would say pin 2 definitely needs to be wired for functionality of the ecu. Pin 1 and 3 are wired for reverse light activation. At least I think. Test it with a multimeter. In reverse if you have continuity between 1-3 and it goes away in any other gear then the power is used to light the reverse lights. I’m betting pin 2 will have continuity to ground in park and neutral but open in any other gear. I don’t have a 3 pin switch here to test or I’d do it.