Mysterious ground wires at DC panel

[peaman]

Presently going through my electrical systems with new electronics and cleaning up 34 years of previous owners' modifications. In the attached image, just below the big yellow 120V cables, you can see a three-way connection of black-insulated wires with yellow crimp connectors in a "Y" fitting. That 3-way is one of five total 3-way connections of black wires. The others are just to the left of the exposed one, each wrapped in black vinyl tape. In each, the stem of the "Y" was connected to a ground strip on the breaker panel, while the arms of the "Y" go up and into the headliner above the panels. Doing the math, we see that there are ten individual black insulated wires disappearing into the headliner to connect to who-knows-what at that end, but all grounded at the panel end. Four of those five 3-ways are of 10 gauge and the fifth is much lighter gauge.

Before I tear into the headliner trying to chase down the path of those wires, have you seen anything like this, or do you know what I'm looking at?

 

[Loren Beach]

In 1988, EY had put several 12 volt positive leads and negative leads to different parts of our cabin lighting fixtures. This allowed one breaker on the panel for the lights, and wires were combined behind the panel with those 3-way crimps. All were well taped and dry and working fine, but I did not like it. I put some long terminal strips behind our panel, screwed to some plywood strips that I epoxied to the hull. I added a 2nd terminal strip for the minus (neg.) wiring, too. This allowed just one wire per circuit to the breaker on the panel, and really tidied & cleaned up the area.
IIRC our 12 volt wiring is 12 or 14 size, and while it was adequate for the OEM incandescent bulbs, now it's probably overkill for the modern LED bulb replacements in all of our fixtures.

 

[Christian Williams]

As Loren says, Ericson combined grounds in various ways and with the complications of added electronics they contribute to the mess.

This 2-part blog entry may add something. (Most of Page 2 of the blog index is devoted to my 32-3)

E32-3 - Part 1--A Novice's Guide to Panel Reorganization

A yacht distribution panel that is a bad hair day from the 1980s is easy to ignore if the boat electronics sort of work. When I changed stereos last year I just crimped and crammed the new wires in. Then a few months later came a new GPS. Soon I...

ericsonyachts.org

 

[G Kiba]

I find it fastening that Ericson used that thick yellow (shore power) cable for their internal AC wiring in 1980's. It looks to be the same stuff used on my Olson 911 to connect AC to the main panel circuit breaker and also to the hot water heater. Upon replacing my shore power connector with a Smart Plug, I found that the wire conductors were blackened to depth too deep to cutback and reconnect. Not sure what the cause was but I am planning on replacing the cable with the now standard marine 3-conductor cable. Additionally, my DC panel is also overwhelmed by PO add-ins, splices, and unattached grounds and wires. I am rewiring both systems and creating a detailed schematic while capturing what is currently there in photos. Not a fun job but learning a lot about how my boat is wired. Which will be handy.

 

[peaman]

As Loren says, Ericson combined grounds in various ways and with the complications of added electronics they contribute to the mess.

This 2-part blog entry may add something. (Most of Page 2 of the blog index is devoted to my 32-3)

E32-3 - Part 1--A Novice's Guide to Panel Reorganization

A yacht distribution panel that is a bad hair day from the 1980s is easy to ignore if the boat electronics sort of work. When I changed stereos last year I just crimped and crammed the new wires in. Then a few months later came a new GPS. Soon I...

ericsonyachts.org

This is great information. Nothing mysterious, then. I am in fact, on the path to following Christian's fantastic blog entries on cleanup in the DC panel, and with that, I will dispose of the oddball 3-way connectors and route those wires straight to a common ground strip. After all of the no-longer-used wiring is removed, I think the boat will float a couple inches higher, at least.

 

[Kenneth K]

Before I tear into the headliner trying to chase down the path of those wires, have you seen anything like this, or do you know what I'm looking at?

Well, if they run forward and into the headliner on a 32-3, they could only be:

1. Any/all of the forward cabin lights
2. Any/all of the mast lights
3. The bow light
4. The 3-way bilge pump switch in the head for the shower bilge.

The easy thing about grounds is that it doesn't really matter where they go, only that they are properly connected to the ground bus bar when you redo.

 

[peaman]

Well, if they run forward and into the headliner on a 32-3, they could only be:

I just wanted to make sure it wasn't some kind of bonding, or lightning protection rig. Thanks.