Ammeter to Voltmeter...who does it?

The circuit breaker looks to be tapped off the side of the ammeter wiring thats coming from the alternator. This may have been an add in by the motor home manufacturer. Not sure. But if it is, and you convert to a volt gage, i would tap it back in where you would connect the 2 ammeter leads together sandwiching it in with those 2 leads and leave it right where it is.