Shell off on a 1986 34' Limited. Time to tidy up the electrical so I can get this critter insulated and the the inner skins back on. The electrical won't see many changes on the DC 12V
side other than a few added USB ports, and perhaps a few lights. For the AC I have most of what I need, including a beautiful Blue Sea AC/DC combo distribution panel and 300 feet of 12/3 marine tinned wire for the 120V. I've decided to stick with the 30 amp AC service. No solar at this time. I'll be making changes to the 120V layout but that's a separate chapter.
wire is 12 guage. I've become accomplished at procrastinating on the electrical because it's such a mess, and the more I read the less clear things become.
I am starting with the easiest first; the 7 pin wiring to the running lights. I've untangled these wires from the 12V
backbone of wires that run down the centre top, and have routed them separately. All connections, wire nuts, crimps, soldered, and spliced with tape connections have been renewed with Wago.
Working from the back, the white ground wire from every running light is daisy chained, then spliced into a single white wire that runs along with the main bundle of 12V wires in the ceiling. This main white ground wire also accepts every white ground wire from the 12V branches. Ultimately one single white wire lands at the fuse panel. There are many splices along the way, in some cases as many as a half dozen white wires from branch circuits splice into the main white ground in one place as it travels forward. In a few cases 12V lights (like an outside light near the door) are grounded with a screw into one of the aluminum ribs, and therefore do not meet with that main white ground.
I'm thinking of running a separate white 12 guage ground from front to back that will host the grounds for all of the running lights, then connected to the 7 pin junction box in the front. Does anybody see a red flag with this approach?
There are 5 interior 12V branch circuits, all of which gang their ground wire onto that main white ground that travels the length of the trailer along the roof to the fuse panel. I'd like to run a separate ground for each of the 5 circuits. I'm unclear as to whether it would be best that each be run to the frame, or run forward to a bus that would then be grounded to frame, or from the bus to the fuse panel that is then grounded to the frame.
At this point I'm not changing much for 12V branch circuits, just cleaning things up. One ground backbone that absolutely every ground feeds into seems risky, but this is the setup that is original to the trailer so is what I'm proposing (separate ground for each branch circuit) out to lunch?