Try contacting the shop that serviced your engine. He should be able and willing to help you out. It’s acting as if there was no ground, but I’m assuming you’ve attached the ground wires. Would seen highly unlilkely that both ground wires in the harness are damaged or that the leads from the box to the battery are damaged. Could the battery be connected backwards?
LAD Specialties customer / tony kart / rotax / kt100