I have a 1982 cm450c. I had everything working well except the horn. I pulled the horn and it was bad so I ordered a new one. While waiting for the new horn I decided to check if power was coming to the horn’s wires. Using my Multimeter I had the red wire in one of the wires and I touched the black multimeter wire up against a ground point. My ignition was on and my lights were on. Suddenly the lights went out and the bike is completely unresponsive. I checked the three fuses In the fuse box and they all test good. The battery tests good as well. What should I check? Is there another fuse someplace?