Look at the box. Each slot was labelled. Also the owners manual usually has the fusebox info. That's the little book in the glovebox (if its still there)
I think one of things you are asking about is the location and bundling of the cables. Some shop manuals that, some do not. I think I've seen it '70 - '71 Plymouth. Often that has to be figured out by looking at the car. In general, there is a 'body' cable connection or two behind the driver side kickpanel.
First narrow what is shorting. Whether its the correct fuse for the circuit, etc.
You can download a Dodge '73 if not a Plymouth Shop manual from Mymopar.com reference section.
