Just got a stage 2 extream automatics with a brake,it is a electronic brake? So I was told reverse will not work without it wired in! So now I need to wire a momentary switch in to it question is,how big amp switch do I need? Also to engage reverse do I need to hold button or just push it and it will go? New to this transbrake deal,so trying to get low down on how and why works that why?