If you just need a set of dry contacts, basically closing a switch, wire your two step to both contacts, if this is the case you should have two wires. It doesn't matter which one.
This would work for an EVC or Greddy EBC.
If you have some other two step boost device that is looking for a 12v input let me know and we'll go from there... If there is only one wire and it is looking for a ground, you need to get an ohm meter and check for continuity from each contact to a ground. This would be a reading of 0 (Zero). Once you find the terminal with a continuity, wire your unit to the other one.
If this isn't clear let me know, dont try to make it work unless you are clear.
You can call me if you wish.
678-907-7133business cell
Eric