Marine Wiring Articles on...Horns
Please could you comment on the boat wiring diagram that I’ve drawn up.
- Twin Verado outboards
- House batteries.
I’m currently trying to wire up a new boat here in Oman (no technical expertise available) and I’m really concerned about dangerous AC currents floating around the boat whilst my family swims.
Please could you have a look and give me your comments as I’m no expert at this?
I know that I’m missing an earth wire from the fused junction!
Any input from yourself will be most welcome.
Very nice diagram!
I have a few comments.
- Add circuit protection at the source of power for your 24 hour emergency bilge pumps fuse panel.
- Add circuit protection at the battery switch for your main DC distribution panel
- Your shore power ground (green) needs to run to your AC ground buss
- Your galvanic isolator is connected between your shore power inlet and the AC ground buss in the green wire
Also, I would consider not connecting the 3 bank inverter to all 3 banks. Instead,
- Connect two legs to the house battery bank
- Connect one leg to the port engine battery bank
- Connect 0 legs to the starboard engine battery bank
This would allow you to completely drain your dc system with the inverter and still be able to start your starboard engine and charge the system through your automatic charge relay
Most marine AC problems occur when the DC ground is not connected to the AC ground. If you boat has an AC fault to a DC component, the common ground will allow the circuit protection on your AC distribution panel to trip and not energize the water below.
Please send me pictures of this project,
Thanks for your input. I’ve updated the pdf (in case you want to use it)
I’ll take pics and send them to you. But, it might take a while as I’m in Oman and it’s a real struggle to source the various electrical components. Nevermind the marine grade wiring (at the local marina they have a bad habit of using domestic grade wiring).
That’s why I’ve elected to attempt all this myself.
I am trying to rewire my 1991 pontoon boat. I have made many attempts on the internet to find schematic pictures or drawings. Do you have any suggestions of where I can locate them?
Thank you for your time,
Pontoon boat wiring schematics are very rare. Most people either start rewiring their boat one wire at a time or purchase a pre-fabricated harness that has wiring for all the components they require.
Our partners at EzAcDc make a great Pontoon Boat Wiring Harness that has connections for navigation lights, docking lights, boat horn, courtesy lights, livewell pump, and pontoon stern light.
This harness will connect directly to any of their marine electrical panels.
Besides the wiring harness, EzAcDc also sells a clever kit to rewire your boat’s original OEM electrical panel. This is one of their best selling items because it makes this previously crappy job considerably easier.
Hope this helps,
I know little about boat wiring so please forgive my ignorance.
My brother has a 22 year old 17′ VIP inboard motor boat with an intermittent electrical problem. The navigation lights and bilge blower were not working.
While we were messing with it we quickly hit the trim switch to lower and raise the motor – immediately the navigation lights and blower started working.
Later, they stopped working and again we hit the trim switch to lower and raise the motor – again the lights and blower started working.
The boat wiring is generally not in good condition. There are splices in the wiring everywhere, but all the connections appear to be okay. The horn and the radio work fine all the time. The battery is good.
Any thoughts you have would be greatly appreciated.
I would start at the battery and work my way to the components.
The common link between the engine trim, the blower, and the navigation lights is their ground system.
- Clean the battery connections. Replace wing nuts with locking nuts.
- Clean the ground connection on the motor – opposite end of negative battery cable. Ensure all connections are intact.
- Check the connections at the blower and lights to make sure they are intact and making good contact.
This should solve your problem,
Saw your site too late, I wish I had seen your recommendations and bought from EzAcDc.
My Problem: I am replacing a rusty dual electric horn on our 44 sportfishing boat. Should be easy, right? Buy new AFI dual trumpet horn, install and rewire to old connections, push button, hear horn.
Well, this is a Carolina boat and it has many interesting little nuances that we have discovered. One of those is the wiring to the horns. I always wondered why the horn sounded weird. Now I know, only one horn (of the pair) was wired.
There is a large gauge wire running to the tower station (white, black and green). This was wired directly to the horn. Two wires ran to the white and only one of the horns blacks went to the black. Therefore only one horn sounded. When I wired both to white and both to black, the dual horns sound for a second, then neither sounds. It makes what sounds like a click, however and that’s all. I pulled the wiring apart and both horns work individually, just not together. I am guessing that they couldn’t figure it out/fix it or didn’t have time to figure it out before delivery.
What are your thoughts?
When the second horn is connected, there is too much of a voltage drop in the horn circuit to power both horns. This could be caused by a poor connection or too small a wire in circuit. It is also possible that the horn button is causing the problem.
Check all electrical connections. Try connecting the new horn directly to the horn button. Test the horn at all possible locations in the horn circuit and you will find the problem.
I bought a 1989 Laser Bass Boat last year. It was one of those “in a hurry to go fishing” purchases.
Anyhow… The guy I bought the boat from told me that it had some minor electrical issues. Well, I’m an Aircraft Avionics Tech for the Air National Guard by profession, so that sounded like fun. Well… It was more than “minor”.
Basically, the harness has been cut out in between the ignition switch box and the instrumentation. I have no tach, fuel, trim, or anything.
Now, I am wanting to install new instruments so they will all be good. But I have no clue as to
Am I screwed or is there help out there?
What brand is your engine? What wire colors do you have available?
Most outboard engine manufacturers have standardized their wire colors, so we should be able to work through this.
It’s a 1989 Evinrude 150 XP. As far as wire colors I’m not sure.
I called a local dealership to see if they could order a harness that I could use. They indeed could get one, but it was $200.
All of the original wires are there coming from the throttle/ignition box, but there is no plug there to go to the instrumentation. I don’t mind splicing it at all. I have access to some great US Government equipment that will make it easy to do.
It’s just knowing what wire goes to the tach pick-up and so on that’s killing me.
- Purple – Ignition power out – connect to b+ on all gauges
- Black – Ground – connect to – on all gauges – you may also need to connect to gauge light ground
- Gray – Tach signal – connect to S on tachometer
- Pink – Fuel quantity – connect to S on fuel gauge
- Tan – water temperature – connect to S on temp gauge (if you have one)
- Brown/white or white/brown – trim position – connect to S on trim gauge
- Blue – instrument lights – connect to Lt+ on all gauges
This should give you a great start.
Let me know if I missed any gauges,
I recently got a very good deal on 16-foot center console skiff – sound, solid hull; no rot that I could find; no major cosmetic issues; engine runs well, etc.
But, while all the electrics work on the thing (except the little Rule bilge pump that needs replacing) the wiring is just a terrifying mare’s nest. Most of the space under the small center console is spaghetti, and lots of stuff is connected with black tape. Bits have been added or had “field expedient repairs” over the years. I’m just waiting for the massive short out and failure.
The total system is:
- A single battery (12V)
- 48 hp engine with electric start, alternator & powerlift (’96 Johnson 48 hp 2-stroke)
- Running lights
- Bilge pump
- Temp and tach gauges
- Depth finder
- A 12 volt outlet.
I would like to add a kill switch, as I will run this boat alone at times. (While I’m at it I MIGHT want to make the system two-battery.)
I’d like everything to be properly connected on a proper breaker board (or whatever the right term is – my ignorance is revealed) and get everything bundled up and out of the way.
Here’s the question: Is rewiring this thing something I can do myself with zero experience?
It seems straightforward. Follow what’s there and replace with good wire and good connections. I’m a generally handy guy, but have never tackled a project like this.
Or, am I simply better off taking the thing to a shop and letting them do it? If so, do you have any guess on the amount of labor involved? Shops here get about $80 per hour.
For a few hundred dollars, you can do this project yourself and have everything new.
I would divide your boat into two electrical systems. Engine and boat accessories.
Engine Side Boat Wiring
The engine side is probably salvageable.
Johnson/Evinrude have used the same wire colors for decades.
- Blue/White (or Blue) Trim up – only connected to your trim switch
- Red/White (or Red) Trim power – only connected to your trim switch
- Green/White (or Green) Trim down – only connected to your trim switch
- Red/purple – Ignition power in – Wire runs from the engine to your ignition switch (may run through a fuse or breaker on the way)
- Purple – switched ignition power – Wire runs from your ignition switch to your tachometer and temp gauge (b+ or I post on gauge)
- Black – engine ground – Wire runs from the engine to your ignition switch (may have an additional wire from the ignition switch to the tachometer and temp gauge for ground.
- Black/yellow – magneto ground – Wire runs from the engine to your ignition switch
- Yellow/red – start – wire runs from your ignition switch to your shifter (start in gear protection) and then continues to the engine
- Purple/white – choke or prime – wire runs from your ignition switch to your engine
I would remove all extra wires that have been added to this system over the years.
Adding a kill switch:
You will need to connect two wires from the kill switch to your ignition switch. These two wires will run from the M and MG posts on the back of your switch (your black and black/yellow wires are connected to these posts) to the posts on the new kill switch marked NC or outboard.
Keep the black and black/yellow wires on your key switch so you now have two wires on the M post and two wires on the MG post.
Boat Accessory Wiring
The simplest way to deal with your spaghetti mess is to replace the wiring. You have two options, One wire at a time or replace it all at once.
My partners at EzAcDc have all the parts to make this a simple DIY boat wiring project. Besides OEM quality components, all of their parts are engineered to simply snap together so even you are assured of correct and solid connections.
Boat Wiring Harness
The EzAcD Standard Boat Wiring Harness would provide every wire you need to rewire all of the accessories on your boat including navigation lights and bilge pump.
Boat Switch Panel
Their Deluxe Fishing Panel would provide the 12 volt receptacle and the switches you are looking for. Another option would be the Standard Fishing Panel combined with the 12 volt Receptacle Panel. As I said, all of these parts plug directly together.
EzAcDc has bilge pumps and bilge pump kits that are designed to plug directly into your new harness.
While you are rebuilding, you may want to consider replacing the navigation lights on your boat as well. Just like the pumps, the EzAcDc navigation lights also plug right into their boat wiring harness. This combo kit would be a great replacement for your existing light systems.
All of the harnesses, panels, and components come with adaptors to connect to existing components. If you decide not to replace your navigation lights, boat horn, bilge pump, etc, don’t worry. Adaptors are also provided to connect to your legacy components.
There are download-able schematics on the site and every harness comes with every breakout labeled. For example, the standard boat accessory harness schematic shows a breakout of 24″ for the navigation light. It has the colors gray/blue and black on the schematic. The harness will have a gray/blue and black breakout that is 24″ long and it will have a tag that says “Navigation light”. This really makes the job much easier.
Dual Battery Switch
EzAcDc also has dual battery switches and battery switch systems that are configured to be manual kits or completely automatic. The kits all include cables, battery boxes, and a ground buss.
Let me know if you have any questions,