Wiring harness design

[dism]

Looking to upgrade electronics on Azzura.

Adding dedicated wiring and upgrading switchpanel for chart plotter, pump, cabin LEDs, external lighting, autopilot and solar panel to existing cabin lighting/radios/nav lighting.

Trying to picture the schematic required to run a day white light/red night light circuits for seperate v-berth reading lights, rear cabin general/nav 'station' and exterior work/relax lights.

Wondering if run a 1-2 run wiring 'spine' fore-aft to split to junction boxes/busbar/switchpanel in aft/mid/fore locatations OR need to run separate circuits back to cabin entrance switchpanel?

I know I need to first write out existing wiring diagram but what is your wiring schematic look like to envisage what to do?

[Iluka82]

I had the same want on iluka a few years back, Iluka already had light fittings that took 2 bulbs (both white incandescent) I was able to replace the bulbs with a red and a white led and rewire a 3 way switch to each lamp. This way each lamp can be switched between off, red and white and I didn't need to replace the whole lamp circuit. I bought the globes and 3 way switches on eBay for a few $$. I have attached a diagram of how my lamps wire.
Cheers Nick

[Phillip]

dism,
There are several things to consider. I had a commercial switchboard and all my lighting is LED. We found that the lights on the switch board were not LED and were in fact my biggest consumer of power. I have changed them for simple switches, but I have a LED light for night time viewing of the switchboard.
With navigation lights you need to consider the 3 situations; at anchor; steaming and sailing. For steaming I have lights at deck level and half way up mast, anchor and sailing on the mast head.
Then you need to consider your radio/AIS/plotter/ depth sounder setup. For each of these to read each other they need a common earth and an earth between all of them [this is so they can see the gaps between the NEMEA data. Very important or they cannot work together].
I ran separate wires port and starboard to pick up the inside lighting and separate wires to each instrument. In fact I ran a dedicated positive from the house battery to all my radio/plotter/AIS via a switch for each with a fuse as I found that power spikes when starting the inboard cause all these instruments to switch off to protect themselves, very frustrating if you had to start the engine in a tight situation and I lost all the days tracks etc as well!
I have 2 house batteries and a starter battery which are all charged by a 100W solo panel via regulators. I have no frig [yet] but do run my autohelm up to 12 hours at a time and I have never suffered from lack of power with that set up.