Momentary (additional) wiper switch - HELP!

[RedBed]

My Dad had an old car that had a (factory) momentary switch on the floor that would activate the wipers. It was REAL handy. I would like to duplicate that in my truck.

So I tried it and (like an idiot) I jumped the wrong 2 wires and fried my switch. So I ordered a new one.

On the 3-prong female plug that goes into the Motor, it appears that the one on the left is 12v always hot. Since I burned up the switch I don't know what the others are. I assumed that the middle was a lower voltage and the right was ground?

My question is, how would I go about wiring in the footswitch?