The wires in these bikes sure look like a mess as they get old but it's really easy to sort out once you take things apart. If mine didn't work ok I would put a new harness together with modern connectors and everything.
But mine keeps on chugging. These are awesome bikes to use for taking to the race track to get around, camping or whatever. I wouldn't trade mine for anything. I can seriously do wheelies on mine, hehe. And these are street legal.. What a bargain.