2001 GL1800 Trike Part ID

[14Bode]

Hey all,

I am new to bikes and I recently had unfortunate events happen where I am not trying to get my father's bikes started. I am currently figuring out why the GL1800 will not turn over. The bike lights up normally but just clicks when I push in the ignition button, this seems to be originating from the rear. I put in a new battery, checked the relays, made sure the bike is in neutral and everything. Looking for wires that mice may have decided to snack on, I found that this wire is in two (manual picture inserted). I hope this is the issue but I will not be surprised if I find more wires chewed up. This picture is under the "reverse switch" section in the manual but searching on Google for this wire/wire bundle, I cannot find what I am looking for. I traced this wire and it looks like it goes into a huge wad of wires that run up the right side of the bike (when sitting on the seat) and plugs into 3-4 sockets on the top right, below the speaker. Does anyone know what this wire is and what I need to look up to replace it?
Thanks!!!

Recap:
Bike lights up as normal.
Starting button only results in a click that seems to be coming from the rear.
Circled wire in the picture attached resulted in a chewed wire.
Tracing the wire, it commingles with a wad of wires running up the right side of the bike, plugging into 3-4 sockets under the speaker.