My new to me 30 C comes with electrical mysteries for me. Maybe someone out there has this setup and can explain what’s going on. All batteries were dead one start and 4 house all flooded lead acid. I replaced the start and removed all 4 house. The 4 house removal crouched in the port lazarette was not a lot of fun for this elder guy! I digress.
Anyway I find an on/off switch and a 1/2/both/off switch below the DC panel. The on/off shows a voltage when start battery is connected at off terminal and at both terminals when on.
I believe this switch is only connected to start battery. Am I right? If so then when this switch is on does it the big on cable go to the 1 on he 1/2/both? And then does the 1 cable go to the starter?
If I have the on/off on and the1/2/both switch to both should the start battery run the house with all house batteries gone?
Lastly where do the red and yellow wires go form the on terminal of on/off switch?
Hi,
I’m guessing that the yellow wire to voltage meter shunt to display the engine battery voltage, this what I have with Victron voltage meter although my wire is red. Someone may have spliced in a yellow wire, which is the wrong colour, for 12VDC yellow is negative.
I believe that yes is single switch is on and other is set to both then start battery will run house devices such as lights. Conversely if the engine battery is dead, the house batteries will start the engine.
You need to look closely at the back of the 1/2/both battery switch. The terminals do not match up with the words printed on the front of the switch.
See photos attached. There is also good article on Marine How To website on installing a ACR that has useful diagrams for wiring battery and switches.
A good way to start is to trace all the wires from and to the switches and draw a diagram. After looking at the diagram you may be able to understand what was done or attempted. Then you can decide how to alter/ improve and rewire with the right colours of wire. Use the right size wire and use overcurrent protection ( breakers or fuses where needed. Label all the wires was both ends. Always approach a wiring job with the idea of doing it right and to the highest standards so it does not have to be redone. Make a wiring diagram, I know I can not rely on my memory. Over time you will improve the electrical system and gain a better understanding for trouble shooting. Take a boat electrical course if you can.
I’m not a fan of the 1-2-Both switch as commonly installed. The reason is that it allows the depletion of the start battery by house loads if the user leaves it in the wrong position. Nobody wants to have a dead start battery just when they need the engine and I personally don’t like having to remember things that important.
I have my batteries wired so that there is no way the house loads can be connected to the start battery. I never need “Both” to start the engine because the start battery is always 100% charged. There is no other excuse for the “Both” setting.
This is a great article by Rod Collins that you should read to get an understanding of the pros and cons of these switches. https://marinehowto.com/1-2-both-battery-switch-considerations/
I argee with Paul. I followed the text and wiring diagram at the end of the Marine How To article he posted. In reading this article you’ll note the author Mr Collins says you don’t need to change battery switches, unless there’s a problem. Then he describes what to do in the text following the diagram. My battery and wiring is set up this way, I never have to change the 1/2/both switch. I have Blue Sea ACR installed as shown in the diagram. Its been this way for 2 years, no problems.
Don
Roger, I’m not sure I can diagnose the current you are getting as described, but about the on/off switch:
It is common to have one to isolate the engine starter from everything, for security and/or maintenance, and for …in some ways to optimize/fail-proof charging systems.
In response to the bigger issue about primary wiring on our boats, I am sharing the attached PDF which has a good description of why and how to layout a more -or -less failsafe house/start battery system; and a comprehensive wiring diagram. This was written by Rich Knowles, well known in Halifax and the maritimes as a boat electrical/electronics guru. Several years ago he gave me permission share this piece and I am happy to do that here. Rich helped me rewire my other Hinterhoeller boat this way during a refit, mine includes solar, shore power and alternator charging, and the separate on/off battery switch as shown on the diagram. In my case, I have a keyless ignition, so for security this switch is in a concealed place down below, secure when the cabin is locked. I have been using this system so far for 3 summers in daily charter service with absolute dependability. Hope some of you might find the attached PDF useful.
Getting ready for launch now!
Greg Silver
Misty Cat 26C #121
St. Peter’s, Cape Breton
Since you would want to be able to use the house batteries to start the boat if the start battery was dead, I would guess that the heavy guage wire from the on/off “on” terminal runs thru the 1/2/both switch to the starter.
The thing that you always want powered is the bilge pump float switch, so maybe this is one of the two small wires on the “on” terminal but it’s switched for some reason. This is easy to check by playing with the on/off switch and the float switch. If the float switch now does nothing then it is likely powered off of the buss bar that combined the four house batteries (before the 1/2/both switch) and I believe that you will need to move it to the start battery side of things.
I hope these comments didn’t further confuse things.
Enjoy the new boat,
Jon Lewit
previous N30 owner
Kingston, NY
I’m not a fan of the total isolation of the start battery and do not have that on my boat as it restricts my choices. Yes, I do have to remember not to run all the batteries down and is why I never have more then one battery on at a time. If you have a fault with your house bank, and your start battery only powers the engine, how do you make an emergency call on your fixed mount VHF??
Joe Valinoti
S/V iL Gatto NS30U #221
Sea Harbour YC
Oriental, NC USA
In that extremely rare case I suppose I would move the panel feed wire from the house battery + terminal to the start battery + terminal but it’s not something I worry about.
Thanks all! I will take a closer look and likely have more questions. I was hoping someone might have the same config on their 1984ish 30C. And could explain how the two switches work together.
I never liked the 1 - 2 - both - off switches. Much to easy to come to a sad end, ot beginning of the day
Adding a Blue Seas Charge ACR made life better, we just left it on “house” and never touched it. The batteries combined to charge when plugged in to shore or when the alternator ran. When we were sailing or at anchor they “seperated” and we were on the “house”. The start battery became the hail mary battery, Maple Leaf fans are still waiting for…
I recently changed the 40 year old maon switch (1/2/B/O) to a newer idea from Blue Seas, “On - Off - Both”. So things are even simpler. When “On” each battery is connected as expected. House to house loads, start to the battery . Combined means both banks are connected as one bank and off is, well, off. I checked with Bue Seas, all I needed to do was connect each “hot” lug to the ACR. I did not need to run all the way back to the battery. But both legs need fuses.
Roger,
Many of the boats were fitted with just the 1/2/B/O switch also called a 4 position switch. They would also often have a split diode fitted as well. On my boat the positive cable came off the alternator and went to the split diode. On the other side of the diode a separate cables ran to each of the two battery banks. This set up allowed both batteries to be charged as long as the main switch was in one of the on positions. The downside is the type of diodes used at the time would drop the voltage by about 1/2 a volt which could lead to the batteries being under charged unless the system was wired such that the alternator sensed voltage on the battery side of the diode. On my boat, a 26C the split diode charger was in the engine compartment.
The extra switch you have suggests a previous owner has made changes to the electrical system so you are stuck mapping out what is currently there.
When I first got my boat, I had battery problems and it turned out to be a bad diode!! Got rid of it and haven’t had a problem since. If I want to charge all the batteries with the engine, I simply turn all of them on. The small solar panel works the same way. When using the 110VDC charger, it has a separate output for each of the 3 batteries. I do not have battery problems due to the simplicity of my system!!
Joe Valinoti
S/V iL Gatto NS30U #221
Sea Harbour YC
Oriental, NC USA
The very inefficient old diode battery isolator was the right idea but ahead of its time. It was there to separate the alternator output between the banks and keep everything charged. Its problem was that it lost so much energy to heat, hence the big fins on them.
You can now use an FET isolator in exactly the same role with around 99% efficiency. No relays or switches involved. The alternator feed goes to the FET, mine is three bank, and it charges the banks according to their needs while keeping them totally isolated.
Here’s a good video by Jeff Cote of Pacific Yacht Systems about them.
FWIW, when i was delivering or looking at friends new (To them) boats, it was not unusual to find, that with the battery switches off, there was no power to the bilge pump circuit.
Joe Valinoti
S/V iL Gatto NS30U #221
Sea Harbour YC
Oriental, NC USA
If the starting battery can’t be drained by house load there is almost no scenario where it would be dead. Its only task is to start the engine which drains very little power and is immediately followed by a period of charging from the engine.
If you can kill your start battery by starting the engine you need to look at the engine.
I wired my bilge pump directly to my battery. (I only had one Deka House battery - it started my engine and was recharged by the engine as soon as it was running). My former boat was (and still is) on a 110 volt powered slip. Of course, the wiring was fused with an an-line, easily reachable fuse. The wiring runs through a standard RULE Auto/Off/Run switch, right beside the 12-volt breaker panel. Except for the pump itself crapping out every three years, give or take (that’s the way it seems to be with these little bilge pumps), it works like a charm and is ALWAYS on.
