Mystery wire coming from battery circuit breaker

[jeremyseattle]

While troubleshooting an issue with my house batteries charging (still don't know what the cause was but it went away), I found a yellow wire under the dash on the driver's side. I traced it back to the generator bay and found that it connects to a post on one of the circuit breakers that I believe go between the coach and house batteries. I'll include a photo below.

While I was having the aforementioned issues with charging, this yellow wire had no charge, but when I checked again later, it was hot (12v). I think something must have tripped the breaker, which auto-reset after I removed shore power. Still unsure of all that.

Anyway, anybody know why there would be a hot wire running from the generator bay to the dash? I don't think it was hooked up to anything before, but I could have knocked it loose - I just didn't see anywhere it may have gone before.

The wire connection is circled in red here...