Alternator wires! HELP!

[Al1940]

I am helping my friend Al with his '68 Truck. He's 77 and doesn't remember why he cut these wires!
I have found a new passion with fixing his truck because he has all the tools to do it with.
The truck starts and runs well but when I pointed out the wires he doesn't have a clue, but may have had a trailer at one time.
The off-white wire and blue wire behind the alternator was cut. Are they necessary?
The white wire coming from "dual battery indicator", middle bolt, cut as well. Not the same thickness or exact white as cut alternator wire.
All help is appreciated.
Thank you!