Hi all, I am trying to trouble shoot my bow nav lights (1981 Catalina 30). The stern light still works, but not the green and red up front. Today I looked into my anchor locker where the lights are located and found tons of electrical tape, non-marine crimps and wire. So I replaced all the wiring from where it disappeared into the hull back up to the lights. Still no lights. Opened my panel and found an amazing birds nest. Now I should mention that all the lights worked when I bought the boat in June last year. So I tried to check for loose or broken connections behind the panel, but didn't really find anything.
So, to my questions. I eventually want to replace the single panel with 6 breakers with something a bit more modern and roomy. In the meantime, I would like to tidy up the current wiring so that it will accept the new equipment with no problem. My first question is this - Do all the negative wires for each circuit end at the buss bar?
All of the grounds should terminate at the negative buss bar or a grounding post.
Is there also, or could there be, a positive buss bar?
There might be, but if there is, it should only be feeding the DC panel. If you have other connections to the 12 VDC positive buss bar, they should be investigated. Some people will connect their charging devices to the positive buss bar, or the post on the battery switch. There may also be things like a battery combiner or echo charger attached to the house positive buss bar to charge the starting battery bank.
One reason the wiring looks so bad is there are three negative wires attached to each lug on the current buss bar. I have purchased a replacement with triple the lugs to help with this problem.
There's a very good chance, if this is like any other PO wiring project, that about half of those wires aren't in use any longer.
To re-wire the forward running lights would I just tap into the wires that feed the stern light, and use new wire to the forward lights?
If you're talking about the bow bi-color, that should work. However, I prefer to separate out each of the individual fixtures on my navigation lights panel. I have the "navigation lights" breaker connected to a fused switch panel. This makes trouble shooting and protecting the individual circuits, as well as having the proper navigation lights on much simpler. I can use the individual fuses to protect the fixtures with the proper size fuse.
I did much the same with the "instruments" breaker, rather than having separate breakers for each instrument, I have a single breaker for them as a group, and use the fused switch panel to protect the individual instruments.
That is my current plan of action. When I checked for voltage at the lights, I had continuity, but not 12v.
What do you mean by you had continuity??? between what two points? For a circuit to work, you need continuity from the negative lead of the fixture back to the DC system ground buss bar and you need continuity from the back of the breaker to the positive terminal on the fixture. If those are fine then you should have 12 VDC when the breaker is turned on.
I should mention that my steaming light and deck light no longer work also. Is this indicative of a failed ground in the circuit?
The steaming light and deck light should be on separate circuits from the bow bi-color. When you are sailing, there is no reason you'd need to have the steaming light on or the deck light on—so they should each be on their own circuit or have a switch for them.
The stern light and bow bicolor are often ganged on a single switch, since you generally have both on at the same time—I have them separated since that allows me to use the masthead anchor light as a white all-around—instead of separate stern and steaming light—when motoring offshore, increasing the distance I can be seen from.
Sorry, but I am learning as I go, so any tips or advice are greatly appreciated.
I highly recommend you get a good book on 12 VDC electrical systems, like Nigel Calder's Boatowner's Mechanical and Electrical Manual.
Also, if you're not 100% comfortable with using a volt-ohm meter, I'd recommend you take some electrical troubleshooting courses at your local vocational or continuing education center. If you take a course on 12 VDC automotive electrical systems, the information for troubleshooting and diagnosing them should be mostly applicable to doing the same on a boat.
BTW, if you're serious about re-doing the electrical system on the boat, I'd highly recommend you read and follow Maine Sail's advice, which echoes my own, on terminating electrical connections. You can find his very detailed post about that subject here
I'd also point out that ripping out all the wiring and starting from fresh, with a good wiring diagram is often easier and fewer headaches than trying to work with what the PO left behind. It will also help you in the future, since you'll know the entire electrical system fairly well by doing so—conversely, if something does go wrong, you'll also know who to blame.