looking to hook this setup up but I was kinda confused on wiring, is there a spare circuit that has juice with the key on that can support amperage draw I don't figure it would be much the control takes 3 amps not quiet sure on the gauge. then I figured I would ground both the gauge and controller to the same ground probably the bracket that there steering column mounts to then from the controller there is a brown and yellow one goes to the gauge and the other to the ecu (purple wire right) does it matter which one goes where? and what wire go I use for the dimmer wire on the gauge?