Well the warning isn't because there's a sensor that's supposed to go into the battery via the acid ports when this motorcycle came out they made a battery with a sensor built in. you can still but batteries like that but they are a little more expensive however it might be nice to have since that warning light goes away. I recently got two 82 750's and am currently rebuilding one of them and learned that from a friend that knows a little about them.

It's definitely coming along however like you said, that wiring looks like a mess - that's going to be a fun time ... lol!

Would have been great if you actually showed the steps instead of skipping the parts where the biked is being worked on!