I have been re-wiring my J29 sailboat BlackJack for some time, by tackling bits at a time. I didn’t have shorts or broken circuits, but I knew it was a matter of time before something major happened.
As I have gone through and started re-wiring, I see that BlackJack suffered from various wiring issues. I’m sure you will find this on any old boat. The issues I found were:
- Dead wires that were not connected to anything
- Bad wires and Splice Jobs
- Old wire insulation going bad
Dead Wires
When I first started re-wiring my J29 BlackJack, I didn’t know where to start because there was a lot of wiring everywhere. I didn’t want to accidentally disconnect the things I needed.
Soon I realized that a lot of the wire was dead. Dead as in not connected to anything.
There were wires for the old KVH/Sailcomp instruments that I removed. That one was on me, I knew about those wires. Then there was a wire loom with a dozen or so thin hookup wires with taped ends. It went halfway across the boat and didn’t connect to anything. There were bundles of coiled loose cables behind the nav station.
None of them were connected. I ripped them all out, and I ended up removing a bucket full of wires.
And that was just the first time around. I started going through more last weekend. There was the wire harness for stereo. And the wires for speakers. Wires for even older instruments. Wires labeled “Loran”.
These wires didn’t connect to anything. I don’t have any of these things on BlackJack. Going through all these resulted in another bucketful of wires to discard.
Bad Wires and Splice Jobs
The previous owner had an inboard engine installed in BlackJack. It was a retrofitted Tecumseh 10hp gas engine, the kind used in generators and go-karts. I did not like it all as it caused never-ending grief. I had it taken out and switched to an outboard motor a few years ago.
To supply enough current to the starter, big, fat battery wires were used. The wire was overkill and even more so now since the inboard motor is gone. These wires had to go.
This battery wire was strange in that it was stiff and brittle. To remove, all I had to do was to bend the cable back and forth by hand a few times and the wire broke easily. Taking them out was still a chore because they were stiff.
Installing an ABYC standard Safety Duplex Cable in its place was trivial in comparison.
There were many splices in all the wires as well. For example, the 4 gauge battery cable connected to 18AWG wire (why?), which then butt-connected to 16AWG wire that went to the electrical panel. The speaker cable had no fewer than 5 butt connectors each.
These splice connections had no liquid tape or heat shrink tubing. Some terminals were getting corroded badly.
The electrical panel was a mess inside with wires spliced here and there. The ground connections all went to an aluminum plate that was screwed into the hull with no waterproofing.
The screws were stainless steel and wouldn’t come out of the aluminum plate. Aluminum and stainless steel cause galvanic corrosion, and this was a perfect example.
Replacing Wiring
In general, all the wires are old. Very old. Therefore, I have decided to replace each cable wire completely from end to end, one at a time. I have so far completely re-done the instrument wiring and the wire cables going to the stern, for the stern light and tiller pilot. These are the hardest to do, you have to crawl into the back of the boat. Well, might as well get them over with, I suppose.
The electrical panel wiring was cleaned up some. I removed the aluminum plate and installed a bus bar for the ground connections. All the ground wires go to the bus bar. It no longer resembles a spider web.
I still need to replace wiring for bow nav lights, mast light, and cabin lights. They are the 3 yellow connectors in the photo above. These will be relatively straightforward. I can easily re-run proper cables throughout the boat because all the dead wires have been removed.
All in all, methodically going through the wiring myself has been very beneficial. I am able to find issues and address them properly.
The electrical system on a J29 should be very simple. In the case of BlackJack, there are only 5 connections to the outside – 4 lights and a tiller pilot. And there are only 6 connections inside the boat – NMEA2000, VHF/AIS and 4 cabin lights.
Some connections are on the same wire, so there really only should be half a dozen or so cable wires needed to run through the boat. These wires do not need to carry a lot of power, especially with the use of LEDs.
It is going to take a bit more work, but I think BlackJack will end up with a very simple and reliable electrical system.
