Im trying to wire a switch that bypasses my nav's speed sensor for the SNS100. Now i have a 3 prong rocker switch. I know typically its just a ground/power hook up and good to go but for some reason im probably overthinking it.

Im wondering on the speed sensor wire does one side go to power and the other to ground and itll work when on or does both need to be to the power prongs and then connect a ground for the switch for it to fully work?

Right now my situation is its allowing me to use my iPod while i drive which i love but my nav is completely horrible and off and slow. At this time i have one end of that wire to power the other end to ground. I want it to be smooth like it was previous to the modification.

Am i overthinking this?