I have a 2000 big bear 400. My problem is Exactly like yours. Previous owner was riding it and it quit in mid ride. He replaced the main fuse in the fuse block and it kept blowing. I traced the wires from the switch after reading the the schematic many times. I got frame power,as you did but after replacing one fuse, smoke came from the CDI. All frame electrical circuits work fine. I’m hoping a new CDI will cure the problem, but considering the cost, I’m afraid the problem might be elsewhere causing the CDI to go bad. I was hoping I could learn on the forum how often the CDI units fail. Any help will be appreciated!