Now that I had a fuse box to take all my wiring to, it was a matter of establishing which cables were good, about to go or gone.
It turned out that pretty much everything needed replacing. The biggest issue was that most of the cables run through the foam sandwich of the headlining and that the cables were the originals from 1968 and simply standard copper. There were no conduits and as the deck connections were the pretty, but useless chrome type ones. Water ingress had wicked in to the cable a destroyed them. I knew that there would be at best a 50:50 chance of pulling new cables through with the old ones but it was worth a try as failure would have meant cutting access panels into the thin GRP headling from underneath which would have looked awful.
Having consulted a rather useful facebook group, I established the route the cables were likely to take and so starting with the main saloon cabin lights I removed the drinks cupboard from the main bulkhead which revealed the access point of the cables into the headlining. It was definitely a case of one out, one in as the cables were on the cusp of breaking. I used copious amounts of washing up liquid as a cable lubricant and came up with a good strong method of joining new and old cables together to pull through without increasing the cable diameter whilst using a minimal amount of electrical tape. I carefully used pliers to get things moving. It was probably more luck than judgement that I was able to pull all new cables through without them snapping.
I replaced all the light fittings with LED’s or LED bulbs, so was able to use tinned 1mm cable for the saloon lights.
The deck electrics were a further challenge as the Freeman spot light cable was pretty under-specified. I replaced this with 2mm tin tinned cable and frankly, it was a hell of a challenge to pull through ! Long nosed pliers were essential for this operation and you definitely need to think carefully which cables you can pull out or need to keep as pull-throughs. This is heart-in-mouth stuff ! Once I’d done the spotlight, I went for the anchor light and finally the socket for the horn. I don’t have a horn yet but replaced the cable to the socket with some 2mm cable as horns can pull quite a bit of power.
The only original wire I kept that ran through the headlining was the one to the wipers which seemed OK, probably because there’s little chance of water ingress having the socket under the canopy.
Elsewhere on the boat, much of the retrofitted cabling was using domestic 3-core cable, often not even using the 3 cores. I removed all of this and replaced with appropriate single and twin tinned cable depending on load. I used 1mm for things like LED lights such as one going to the heads which required me to pry the thin mahogany-faced ply back inside the heads compartment (It’s tacked into place with panel pins) and route the cable in the cavity rather than tack the cable to the outside of the bulkhead. It is a pet hate of mine to see cable attached to the outside of things with p-clips when a bit of thought and effort could hide them.
I replaced the navigation light bulbs with LED’s too.
Finally on the wiring side of things I replaced any cables which had unnecessary joins and got rid of any bodges, such as wire twisted together and covered with electrical tape. I also got rid of as many connections made with ‘chock-blocks’ as possible, replacing with new cable runs or making up proper terminals. I also made sure that all cables were supported properly with cable saddles using cable ties in case anything needed removing in future.