Most such devices are simply ignition cut-outs. You can't start the vehicle without a plug (or similar device) in the jack, supposedly making the vehicle harder to steal.
Karr is now seems to be part of Southwest Dealer Services. The anti-theft ignition devices have fallen out of favor, but they may still be able to provide some tech help on the old system.
SouthWest Dealer Services | Karr
But I suspect you can figure it out on your own. The wires either interrupt the ignition circuit or ground it out unless the plug is in place. Study it for a bit and you will probably realize which technique is used and how to remove the Karr box from the circuit.
2004 American Tradition; 2014 Buick LaCRosse
Homebase in the Ocala Nat'l Forest near Ocala, FL