wiring/charging issue

so I've got a 77 xs650, when I first got it a few months ago it seemed like it had a charging issue because the battery would die about every two weeks, I did the slap test and checked the bike out with a multi meter and everything seemed fine so I assumed that it was they way i was riding the bike(in the city stop and go) that prevented the battery from charging.

Now the battery dies much faster and it fails the slap test and doesnt seem to be charging when check it out with the mullti meter. I was looking through the wires i noticed some fried wires(I have attached pics).

I'm assuming this is the problem in my charging system, but what could have caused this? Do I have to replace the whole wiring harness? is the regulator bad?

any help would be very appreciated.
thanks.

Marginal batteries tax the system.
Leading to overheating. Have someone load test the battery.
Check your brush length.
Clean and check the resistance on the rotor.
Then check the stator if the problem hasn't become apparent.

Re wiring, I can't tell by the picture. Is it down to bare wire? If so I guess you would need good wiring before doing other things.