ok am trying to understand this goin from the hondata website, i have a 96 civic on the ecu do i hook up the wire to b8 or b5 and a15 or a20? and should i have a ground going to the switch right?

 

let the ecu read the ground trough the switch!

wich input or output you'll use, you can probably select in the s300 software.

in ectune i can choose from a dozen inputs or outputs, just browse trough the program

 

Correct just choose which ones you want to use in the software and wire accordingly