Boat Electrical Wiring Made Easy, Part 2, Switch Panel Wiring, Cabin Light Wiring - Complete Guide

Boat electrical wiring from scratch: Part2. In this part we take wires from the electrical master switch to the boat main switch panel, and also from the 'negative earth' bus-bar to the switch panel. We consider the total current draw the we need to cater for in the main switch panel and the wire gauge needed to be safe for the maximum current draw in the boat electrical system.
As we go through the wiring step-by-step we look at the types of connectors, covering size of connector, soldering of the connector to the boat electrical wire, and using heat-shrink to minimise the risk of accidental short circuits in the boat electrical system.
To keep the wiring organised and tidy in the boat, we look at screw mounted retaining pads, and tie-wraps to keep the wire runs in place and looking neat. When installing the boat interior cabin light we look at the method of attaching the light to the ceiling of that boat, and we also extend the wires by soldering some extension wires, using heat-shrink to cover and protect the soldered joint. During this part of the guide we work out some difficulties with wire electrical terminal ends, and find a couple of solutions to make sure the terminal ends fit the wire as well as fitting the electrical fittings that wire is going to be connected to.
As we power-up the boat electrical system for the first time, we talk a little bit about the need for taking care with the possibility of accidental short-circuits when working around batteries (boat and car 12V batteries have a large current capacity and great care should be taken to avoid short circuits especially when using metal tools like spanners near the battery terminals)
When connecting up to the boat main switch panel we look at the main feeds to the switch panel, as well as the individual leads that come from the switch panel to take the positive side of the circuit to the individual electrical components being fitted to the boat.
The negative 'main feed' wire from the bus-bar to the switch panel (for this particular switch panel) actually is only needed for the purpose of illuminating the rocker switches - the circuit is completed for each individual items by taking the negative wire from the component, directly back to the bus-bar.
In this example we chose 10-gauge wire for the main feed wires to the boat switch panel, to cover the maximum current draw of 30Amps (6 switches x 5Amps). This was needed for the positive feed wire to the switch panel, and we chose also to use 10-gauge wire for the negative main switch panel wire for consistency, even though in actuality for this particular switch panel the negative main wire is only powering the illumination of the rocker switches.
At the end of this Part 2 video we show the boat cabin light working. In the next video (Part 3) we start looking at incorporating bilge pumps and float switches into this electrical system.

[@bethanybertelsen5608]

I’m working on a project 22 foot sailboat. I’ve stripped all the old wiring in it and you made it easy for me to understand how to wire the whole boat I like how you broke it down from the beginning from scratch thank you

[@keithd472]

Excellent explanations in clear, easy to understand language! Keep these coming as your demos are very useful to people like me who are refitting a boat. Thank you!

[@michaelkaarls5789]

This video series is perfect. I am sitting here watching ordering parts and wires as I go and can't wait to watch it over while installing items in my little runabout, Cheers for your work with sincere thanks from Victoria BC Canada

[@BoatFittings]

Hi many thanks for your kind comment. Kind regards, Richard

[@labradorshalladore4966]

Thank you for your time and your series of videos

[@brentwalthall9690]

Exactly what I needed. Thank you!

[@BoatFittings]

Glad it helped!

[@brianwest1501]

Good job. Great knowledge.

[@Axel-xp8dx]

Danke für die großartigen Videos

[@Stevecollinsclear]

awesome - love your work ❤

[@andreaselme4127]

Excellent tutorial!

[@aja9469]

Thank you so much! I needed this exactly

[@BoatFittings]

Hi thanks for your comment - glad you found it useful!

[@WeAndTheSea]

Great video! Thanks a lot for making this.

[@BoatFittings]

Hi thanks for your comment - glad you liked it!

[@offgrid8204]

Absolutely great video and explanation.

[@TheRemyRomano]

Very nice. Remarkable workmanship too!

[@StefanWoldekidanKunskapsskolan]

Thank you! Great vid, easy to follow and really well explained.

[@BoatFittings]

Glad you enjoyed it! Next one coming soon

[@garethallen2531]

Thanks mate, your effort is really appreciated.

[@BoatFittings]

Many thanks for your kind comment. Richard

[@denisconnaughton2923]

Excellent video again. Cheers.

[@BoatFittings]

Hi Denis, thanks very much for your comment.

[@SVBLUEBELL]

Perfect video step by step

[@michabasinski1292]

wiring had never been easier! Thank You!

[@anthonyhawk5977]

You explain it very well. Thanks.

[@BoatFittings]

You are welcome!

[@easemailboxes]

Thanks so much for pt1. Really made it easy as does this pt2.

[@BoatFittings]

Glad to hear that these are helpful. All the best, Richard

[@jacobread9650]

Thanks Martin kemp! Very helpful!

[@BoatFittings]

Thanks - I'll take that comparison any day! Richard

[@kenhoever8245]

Excellent tutorial, keep them coming. Thank you!

[@BoatFittings]

Thanks, will do!

[@eoinmcmahon1323]

Of all the boat wiring videos i have watched i now understand the wiring circuit set-up. Thanks

[@polarambassadors6777]

Hi ! Just what I needed ! This is by far the best tutorial I've seen so far. Thanks for making the effort of building this small wooden house ! It clarifies everything.

[@BoatFittings]

Hi thanks for your kind comment, particularly with regard to the 'wooden house'. Even though this was quite a lot of additional effort, it seemed better than having a big jumble of wires on the bench. All the best, Richard

[@jasonreynolds2295]

You explain this so well and simply, even i can understand it. 👍

[@brianwest1501]

Really good job. Clear, concise, and to the point.

[@BoatFittings]

Much appreciated!

[@mjway5457]

Another great video. Job well done.

[@BoatFittings]

Hi - thanks for your kind comment!

[@razorsharpbt7666]

Great demonstration and I really like the model you made. Thank you, sir!

[@BoatFittings]

Hi many thanks for your kind comment :)

[@TMsite12]

Great video for a person like me! Thanks a lot of taking the time to create it.

[@BoatFittings]

Glad it was helpful!

[@Jolie_sailor]

Thank you for this instruction.

[@BoatFittings]

You are welcome!

[@lukasgr7821]

Great videos! I realy like the way you explain everything :) Thank you!

[@BoatFittings]

Hi thanks for your kind comment. All the best, Richard

[@SV_Kittiwake]

Great video. I have just pulled out all old wiring. Perfect timing for me these videos. I’m looking forward to part 3

[@BoatFittings]

Hi Chris, thanks for your feedback. It is great to hear that you are finding these useful.

[@helminenjuha]

Beautiful worksmanship, masterfully presented. Thank you so much, very useful with my boat project!

[@Hippp_Magic]

Thank you very much, sir! Superb lesson!

[@BoatFittings]

Glad you liked it!

[@OldGuySailing]

I appreciate your video. I have to wire up a Carl Alberg Sea Sprite. I have always been afraid of wiring but after watching you. I got this !

[@simonpeteradventures7187]

Just what I need right now I’ll go find part one first thank you ❤

[@BoatFittings]

Hi thanks for your kind comment - hope these are useful for you. Kind regards, Richard

[@ciderpress6656]

This is an excellent series of videos. You explain everything so well, it is a joy to behold. Truly!!

[@badabing771]

very educating. Thank you.

[@BoatFittings]

Glad you enjoyed it!

[@Only1Feckitt]

great fun. thank you

[@nonyabusiness3953]

Great video! Just the right information I needed after looking at this birds nest of wiring to be re-done on my 21ft ⛵️. Awesome "how to" learning content.

[@BoatFittings]

Hi thanks very much for your kind comment.

[@JavierGonzalez-xg2tq]

VERY useful! Wonderfully explained and edited. THANK YOU VERY MUCH! This will help me rewire my old COMPAC 16

[@BoatFittings]

Hi Javier, many thanks for your kind comment!

[@rockydubois2418]

Definitely the cleanest and most precise boat wiring installation instruction video I’ve ever seen! Subscribed.

[@BoatFittings]

Many thanks - I must try and get the next video done soon, thanks for subscribing!

[@TheLogozz]

Brilliant stuff for a newbie and so calmly and clearly explained - educational talent right there! Would stay away from it myself, but in an emergency one might have to touch stuff hands on, and always good to have an awareness when discussing with professionals that I would hand things over too in any non-emergency situation....Many thanks from Sweden!

[@gjaynarvasa8624]

Well done!

[@BoatFittings]

Thanks for your comment!

[@nixxonnor]

Very impressive demo. You even took the time to build it to scale and paint it :)

[@waterboy8999]

Brilliantly simple, but very well explained, thank you very much. I didn't think it was rocket science, just a bit overwhelming seeing the back of the control panels, but I did think its only one wire at a time.

[@BoatFittings]

Hi thanks for your comment. Yes they do look a bit overwhelming at first glance, glad to have simplified things a bit for you. Richard

[@waterboy8999]

@@BoatFittings Thanks Richard, you certainly have, most things can look very complicated at first, like what are those rope for!?

[@adelbadawy7861]

Best instructor and best tutorials. Into the point without any complications

[@BoatFittings]

Hi many thanks for your kind comment. Kind regards, Richard

[@TaylanYalniz]

Excellent video tutorial, helpful, step by step…

[@BoatFittings]

Hi many thanks for your kind comment. Kind regards, Richard

[@rickdeadman8017]

Great thank you. So useful.

[@BoatFittings]

Hi thanks for your comment - glad you found it useful. All the best, Richard

[@1ethanb]

thanks mate you've saved me a fortune

[@BoatFittings]

Hi thanks for your comment - glad to help! Richard

[@belindablack9209]

Sooo looking forward all your vlogs. You have been the most helpful to date. I bought my boat, a real fix me upper, I am absolutely loving it. Wish I could start my own vlog but hey, lets's see. Thank you for your content. Exactly what I need. Take care.

[@BoatFittings]

Hi that's really kind - thanks for your comment. Good luck with the boat. All the best, Richard

[@getaswordactual8766]

Excellent video Richard, both parts have made what could be a confusing problem, very simple. I plan to refit my electrics this winter, so will keep a close eye on your videos.

[@BoatFittings]

Hi Many thanks for your comment, happy that our videos are helping.

[@martinkoche4375]

Very nice your a kind soul great video

[@BoatFittings]

Hi thanks - glad you liked the video. Richard

[@aa1405]

Excellent videos! Just bought a boat that needs a bit of work. This will help me a lot!

[@adamhoulahan3572]

This is great, thank you

[@BoatFittings]

You're very welcome!

[@carlosrosa1965]

A god send Thankyou heaps

[@athmss]

Thank you very much again. Very very useful. Congratulations. Alex from Brasil.

[@BoatFittings]

Hi many thanks for your kind comment. Kind regards, Richard

[@jesus3901]

Thank you.

[@macfarlanenz1]

Excellent

[@a.b5140]

Sir, your videos helped me so much in rewriting my boat. Thank you for the breakdowns of everything you made electrical simply.

[@BoatFittings]

Hi - thanks very much for your kind comment, I am very pleased that you find these useful

[@andrewbrown2063]

I have found it easier to understand once I get the concept of a circuit in my mind. A circle; starting and ending at the battery going out to the appliance on positive and back from the appliance on negative; with the various switches and fuses on the positive side. Good videos, thanks.

[@Yeaitstemp]

So glad i found you im doing a complete refit on a bristol 27 almost done with glass work and goin to start electric system soon only area i wasn't sure about

[@BoatFittings]

Hi thank for your comment, I hope your re-fit on the bristol 27 goes well. Kind regards, Richard

[@jamesneirinck413]

Great how-to videos so thanks for putting these out. You commented you prefer solder vs crimp connections. My experience is driven from aircraft standards and those specify crimped connections using good quality AMP / aircraft grade terminals that crimp both the stranded tinned wire and also the insulation covering the wire. Also need to use a good quality crimp tool for this purpose. If you use low quality automotive style terminals and the simple single point crimp tool they only crimp to the wire and poorly at that and will fail if you pull on it. The correct AMP / aircraft style double crimp connector crimped with a good crimp tool will not pull out or fail. We tested them to failure and the wire will always fail first (so as strong as you can get) and the crimped connection remained intact. The crimped aircraft terminals are done that way for the strength but also for the same reason we use tinned and stranded wire, never solid wire, because of the possibility of flexing and vibration which is the same type environment on a boat as on an aircraft. A soldered connection is more prone to fail if flexed or subject to long term vibration. The added benefit of using AMP / aircraft grade crimped terminals is it is easy to do a new connection or add another terminal on the water as you don’t need power for soldering or the soldering equipment. Easier to carry a good quality crimp tool, wire stripper and extra terminals. Just a suggestion for you to consider or try yourself.

[@jeffclapp7330]

As a note, ABYC Standards do not allow solder as the sole means of connection for an electrical connector. You can crimp AND solder, but solder by itself is not permitted. So if your boat may be subject to ABVC Standards (or you want to meet typical standards) then crimping should be used or used as well. Not probably an issue based on the accent in the video, but I'm not sure of Euro/UK standards and if they differ.

[@jeffgriglack9624]

@@jeffclapp7330 I believe that soldering is not recommended because it can make the wire more brittle. You want the water to be flexible. Also, he "tinned" the wire with solder, but he should have already been using tinned wire.

[@BoatFittings]

Hi many thanks for your detailed comments / suggestions. I agree that good quality crimping tools and the corresponding connectors make for a robust solution. In many cases though people use cheap and nasty crimp tools leading to a poor joint, which in my opinion makes soldering more reliable compared to many poorly crimped connectors. I do take on board your comments though, and thanks for making them. Kind regards, Richard

[@timber5893]

Looking forward to the rest of the series! I'm relying on the first to videos on wiring my old bass boat. Incredible job, sir. Best wiring explanation on all of the internet. You deserve greatness.

[@BoatFittings]

Well thank you very much indeed for you kind comments. I must get on with the next one very soon!

[@IdleWind]

@@BoatFittings soon indeed! Please. 🙂

[@debianlinux9448]

Wow!! This guy is true professor!! He explained in great detail yet made it very simple for us non electrical people.. thank you so much!!!

[@BoatFittings]

Hi thanks very much for your kind comment

[@John-ps7mk]

great tutorial.

[@BoatFittings]

Hi glad you liked it. Kind regards, Richard

[@kimberlyjacobsen4148]

I would use the brother label maker pt-e500vp. It can print on heat shrink. Love it. And it was surprisingly affordable.

[@brianfedie8046]

Nice, Thanks!

[@BoatFittings]

Glad you liked it

[@givansolis7687]

Very nice, I'm a rookie at electronics and I understood very well I'm waiting for the part 3!! 👍🏻

[@BoatFittings]

Hi thanks for your comment - I will try to get Part 3 out shortly.

[@deang5622]

It's electrics, not electronics.

[@CGV.69]

Excellent videos! Happy new subscriber 👍

[@BoatFittings]

Hi thanks for your kind comment, all the best, Richard

[@amirbarmaor]

Thanks for this great video. All I need now is to find a boat and apply it ;-)

[@2frogland]

crimps are normally preferred in harsh environments, great aid for the diyer

[@danielboughton3624]

Which is why they are used on automobiles and pretty much everything else. There are people who insist on soldering everything because they had a crimp they did go bad but they can never answer why a 30 year old car still has good crimps. If you are going to solder then get solder connectors v.s. using crimp ones and then add shrink wrap to provide some stress relief as well as short protection. The big issues with solder beyond the time to do it are corrosion due to the flux and cracking due to the hard spot. Modern solders also take a lot of heat and that means melted wire covering which is perhaps why silicon is being used here.

[@galaxys7650]

Im an automotive technician. One tip i have for soldering those big wires- don't use an iron. Use a mini torch (butane), and head the wires with that, carefully, and fill with solder. It is much easier and quicker

[@barrel_brd_bskt]

Thank you Sir 🙏

[@BoatFittings]

Hi thanks indeed for your comment. Glad to be of help

[@andrewcase9652]

Very well explained and looking forward to Part 3. I am hoping you will deal with the challenge of multiple interior lights and running out of switches as the series progresses . Thanks again

[@BoatFittings]

Hi thanks for your kind comment. Thanks for your suggestion on looking into the wiring of multiple lights - I will keep this in mind for one of the videos in the series. All the best, Richard

[@hoverwatch4131]

Can you run a busbar for all your led lights back via a single wire to the switch/breaker to avoid overcrowding the switch with more and more wires as lights are added (or any other system where things are added on. Subject to load obviously).

[@hoverwatch4131]

Great videos by the way

[@marcassuibhne]

@@BoatFittings looking forward to seeing this. ☺

[@danielcookeb90]

Hi Richard, brilliant series. i've just discovered your channel and will be bingeing your back catalogue every day! What a mind of information you are! Even just to remind oneself before carrying out a "job" your series is brilliant!. I have an old 1992 35ft Nimbus DC currently based down in Cornwall (legs reconditioning!) with so many jobs, my early retirement will definitely not be idly spent! And if you ever want to set up a boat series, I'm happy to work with you to make it happen! I have 2 x VP AD41's on sterndrives, so plenty of electrical stuff to work on both engine and domestic!! I dearly want to replace a switch panel on the helm station, as the bakelite switches are all perishing, and was wondering if you have contacts other than the usual large distributors that I might try finding old replacements? New may be better for waterproofing, etc, but will change the look substantially? Keep up the great videos. regards, Daniel

[@carlmarks2199]

Wow, now all I need is a boat.

[@BoatFittings]

Better go and get one then :)

[@paulcapell5676]

Your videos are helping me understand the system thank you . Is the buzz bar the same as ideal as hooking up a fuse bar . Thanks.

[@drewboardman9109]

Great video. Would love a part 3. Also, would you be able to explain how one would add maybe a second/third cabin light - or possibly fans? Would you need a new switchboard?

[@BoatFittings]

Hi thanks for your comment, and suggestion. I will be doing something on adding more cabin lights in a later part of this series. All the best, Richard

[@Alan-dr5by]

Thank you very much for these videos. Just what I needed to know. I did wonder what the wiring sequence is for the circuit as a whole. e.g Battery-Fuse-Switch-Device or Battery-Switch-Fuse-device? Would be good to understand if you could tell me.

[@belindablack9209]

By the by, please do not stop posting.

[@BoatFittings]

Hi thanks for you comment. I am planning out part 4 now, so hopefully not too long away. Kind regards, Richard

[@roberth7929]

Just my opinion, but I’d crimp the electrical connections. Solder only belongs on printed circuit boards. Love your videos!

[@stevero2581]

Awesome videos. Could you do a part 3 where you go on a boat that has a popular setup and show us these components where they would usually be?

[@stevero2581]

For us non boat owners

[@BoatFittings]

Hi thanks for your suggestion. I will keep that in mind if the opportunity comes up. Kind regards, Richard

[@jesusismylord1496]

Nice education video...can you do one about passing a electrical inspection on a boat please

[@BoatFittings]

Hi thanks for your comment. As for passing an electrical inspection, well I think the best approach is to check that all is safe and sound as far as you can tell. Then when the inspection comes, if there are things that need sorting out then that is all to the good, as you will have had an expert come and check your boat and any feedback from the inspector will no-doubt be for your own safety. Best of luck, Richard

[@ilhanaysan]

Please, sir, make a note in the video about soldering vs. crimping the “crimp terminals” used in the demonstration. Crimping is superior to soldering in marine environments. The pull test comparing a soldered connection and a crimped one you mention in some comments ignores the fact that the solder is brittle and is prone to fatigue failure in the long run. A crimped connection will not suffer from fatigue. This advice assumes that both the soldering and crimping are done properly. But also please keep in mind that soldering is a skill that needs to be practiced. Given an inexperienced audience in both, it’s easier to make a bad soldered connection (even with the best soldering stations, which are expensive) than to make a bad crimped connection (requires less skill and good crimping tools are cheaper than before these days). Kind regards.

[@pierrec1590]

Have you ever tried using a propane torch at its lowest setting? Works great.

[@BoatFittings]

Hi thanks for your comment - I do like the little micro-torches for this kind of stuff. Kind regards, Richard

[@rhodevans6523]

Brilliant explanation! Thank you. Could you also explain how the alternator from the engine connects to this system to charge the battery? Thanks again.

[@BoatFittings]

Thanks for your question. I may do a battery / charging related video in the future. Kind regards, Richard

[@derykmacleod4979]

I try to crimp the connector first, then solder it, then slide a piece of heatshrink tubing with the glue inside it. It's a bit of an overkill but ya hope to only have to do it just once lol.

[@mistercaptain2000]

The amount of positive comments is testament to how great your videos are. Thank you. I have a question: why couldn’t I use the negative bus bar on the switch panel for individual negative returns? On my switch panel the negative bar is of a similar gauge to that of the positive one, making me think it should handle the current that would return through it if I connect the peripherals there directly. Also, if no peripheral negative returns go to the panel bar, then why do you need the fat return from panel to battery? It would seem you would then only need a cable to handle the current from the panel pilot lights?

[@BoatFittings]

Hi thanks for you comment / questions. I don't want to comment on your specific switch panel, but I if your switch panel has a good sized negative bus-bar then it would seem reasonable to make use of it. For your second question, the 'fat' negative return cable was used mainly as it came as part of a set (positive and negative) than the need for a fat wire. Kind regards, Richard

[@danieltoledo2979]

This is the reason i pay for internet. Thank you !!!!!!!!!!

[@BoatFittings]

Ah thanks very much, you are very kind. All the best, Richard

[@chadb6336]

Very well done, I’m learning a lot! I’m feeling more confident in rewiring my new, old boat. I look forward to the next one. Is the bus box just for organization? Could you just join all your negative cable’s together?

[@BoatFittings]

Hi I am glad to hear you are getting more confident, yes as you would see in the Part 1 video, the bus-bar is a convenient and organised way of connecting all the negative's together. All the best, Richard

[@wellyftw]

This is really useful for someone trying to figure out the wiring in their narrowboat! A question I have is for when you want to wire up multiple lights. Because the wiring is all hidden on my boat, I'm not sure how it's currently wired up. What would be the most likely way that they've been wired up? I can see on the switch panel there is just one switch for internal lighting. I have two lights which aren't behaving properly - one of them is not lighting at all and putting my multimeter on the wires to the light shows 0 volts, and the other at the front of the boat just flickrs although it lights dimly and so trying to work out what the problem might be. Any suggestions of where to start looking? Thanks very much!

[@velianlodestone1249]

This is great! Looking forward to the next episode. Question, I'm using fuse blocks instead of bus bars / fuse boxes - my boat has two cabins with the engine in between. Would you recommend having one fuse block per cabin (running a big, but only single wire through my engine bay rated for the fuse block. Or would you run individual wires to the seperate cabin and keep things centralised?

[@BoatFittings]

Hi thanks for your question. I think it would be no problem to have individual fuse blocks in each cabin if that makes sense for your wire runs. The only thing I would add is to keep things obvious and clear for yourself, but more importantly for the next owner of your boat. I guess from that point of view people might expect one fuse block, so I would suggest finding a way of making it clear and easy to find that there are two fuse blocks if you decide to go that way. All the best, Richard

[@redwood1957]

Your battery needs a fuse to protect wires. I also would put a switch to isolate the main panel

[@samuelcarlsson7728]

Great video! I have two led strips. How do i wire them so that they both turn on with one switch?

[@vanessatait3184]

great video, so am I right in concluding that by runnung the negative wires through a bus bar that the electrical curcuit is now grounded ? Even though its not earthed ?

[@RechargeableLithium]

I definitely would not solder any joints on any vehicle subject to vibration. Solder turns a flexible, stranded wire into a solid core, which will fatigue and break when vibrated. Crimp terminals should be crimped; then covered with double wall, glue lined heat shrink tubing to waterproof them. Crimp connections are easy to get right with a little bit of practice, and good quality crimpers are readily available.

[@OldGuySailing]

Hello What kind of soldering iron are you using ? Thank you for the videos

[@petemac8229]

curious why you run the component ground/negative all the way to the bus bar versus just writing the component circuit to the negative switch bus? What drives the choice? Assuming the switch is at the front and the bus at the back would you just run the wiring to the closest ground? It may make sense as you build out the boat?

[@kristofmihaly]

Great video, very clear and well explained! I have a question though: Why does the black wire needs to be so think which goes to the switch panel? It supposed to supply the negative only for the lighting of the switch panel, which is like 6 LEDs. Or did I misunderstand?

[@BoatFittings]

Hi thanks for your question. Actually the negative wire happened to be part of a set purchased together, so it seemed a shame to waste it. Other than that no reason at all, and a lighter gauge wire would have been absolutely fine - well spotted. Kind regards, Richard