On my '83 - 16 S, the shore power cable (20 A) is in a small box below the chassis and I'm thinking of modifying it as well. There's also a second cord with a female end crammed in that small box. I'm thinking of rebuilding the box as the wood looks pretty iffy, and it also looks like a good place to add some storage since other than the tongue area, there isn't any real storage to speak of with the top down. It also has a separate AC input connection in the top section, but since I won't be using AC I'll probably re-wire the outlet that that goes to to the regular shore power system.