Help! Mysterious Short from a Rectifier Wire - 77 KZ400

I just got a 77 KZ400 for a fall project bike. The good news is that fired right up after replacing the spark plug boots and putting a little gas in it.

Bad news is that the wires to the battery began to melt this afternoon when I tried to start it up. I replaced those wires and checked the harness and everything seemed to be fine. But when I attached the battery, I immediately got a spark on the terminals. I traced the issue back to the white/red wire coming from the rectifier. For some reason, I'm getting continuity between that wire and ground. Can anyone shed light on this and what I should do?

When I leave that wire unplugged and only connect the battery to the white wire and grounds, the bike starts up fine -- no short at all. But clearly the white/red going into the rectifier is an issue. Help?

Mine did that once , check the solonoid wires one of the terminals on my solonoid was touching the wire going to starter. All fine till I tried starting then the wires got hot /smoking. Only when trying to start.

Just an update to say that replacing the rectifier resolved the issue.