Slow build 71 Scamp 440

So some weird gremlins on the Scamp. Back lights went out………. Easy enough. It was the 20amp fuse. I may have caused that messing around with the deck I installed.
Then I went to start it and nothing. So I started the troubleshooting.
Checked battery Good
Check everything before the firewall Good
Checked in car Nothing
Fiddled with wires at firewall connection (outside)!! Bingo
Looks like we’re at that stage.
I’ll pull it all apart and clean it well and run an extra wire from the alt to the battery.