From where you've posted this, I'm guessing your Argosy 24 is a motorhome (mine was a trailer) but I believe they used the same boat anchor...er.. Univolt converter-charger. If you're upgrading to a modern one (which is a great idea) you're likely to need some modifications anyway since the old Univolts has the fuse block built in. Modern replacements are either stand-alone converter-chargers like the Intelli-power PD92xx series or the Boondockers, or the "power center" type that also include 120V breakers and
12V fuses.
I've attached what passed as the electrical schematic for the
12V interior system in my '75 Argosy's owner's manual. It shows the general idea... big fuse inline in the lines to the battery, a
12V fuse block for power distribution within the coach. I set mine up so that the charge line to the battery tied in to the same lug on the fuse block where the output line from the converter came in, with an inline fuse close to the battery and the battery negative connected to both the chassis ground and the converter negative. There are likely some nice photos of the excellent OCD installations many people have done in various threads on this site.