I've done remote starts for the last ten years and have yet to see one that was installed properly cause any damage to a ignition switch. If your comfortable enough in doing so you can just follow the wires from the remote start to the main harness and cut it off and tape it up. Do this for all the wires from the remote start at least then you can eliminate any wiring issues. If it is a 2000 or newer it will have a security bypass which makes things more difficult.