Check for voltage TO the relay when you push the starter button. You should get 12V. If not, you will have to start backtracking to find the open circuit. I don't have a Rebel wiring schematic, so I don't know the order in which to check things. There are a lot of parts involved. There is the ignition switch itself, the starter button, the kill switch, the sidestand nanny switch, and the clutch nanny switch that current has to make it's way through before it reaches the starter relay. You can test the relay and starter by running fused jumper wires directly from the battery to where the 2 small wires connect to the relay (only the positive wire needs to be fused. This is just in the unlikely event the relay is shorted, to prevent setting the jumper wires on fire) The relay should click and the starter should turn over. Because this bypasses all the safety switches, make absolutely sure the bike is in neutral before doing it.