And So It Starts,i Get Intimate With The Boat.

[mikeyboy1966]

My work in progress so far,

I need to order terminal insulators,wire and connectors so this will stall till new year.

[mikeyboy1966]

I think the interesting thing I’ve learned so far,

and I’m sure a lot of you guys will be in the same “boat”( )

over the years things have changed with a 40 year old boat.

previous owners fit/remove/add.

my Broom has at least 3x fuse boxes/distribution points and two(engine,domestic )isolators.

plus a few bits and bobs added to the battery terminals,which,I’m not 100% sure where they go yet.

to my point.

between the batteries,isolators and the fuse boxes there are NO fuses.

yes,all of the systems are fused,either at the distribution point or the appliance,

And  I guess ,a short would only burn out a smallish gauge wire,but some of the wires run next to all sorts of stuff.

the big“ but”

some of these unfused  cables,to the isolators,alternator,etc can carry 200 amps + before they would burn out.

hmmmmm food for thought

[annv]

Hi Micky I would suggest you make a wiring diagram listing all items etc this will come in handy if you get a problem or you add to to the boat in the future plus it will help any body you sell the boat to too work out what's what, i have a folder on my boat listing EVERTHING including where it is located on board along with a loading list of all items on board. John

[floydraser]

That's a nice neat job, well done. Any BSS examiner would be on your side as soon as they saw this; they would have to look hard and split hairs to find fault. Any potential buyer of the boat would also be pleased to see it; someone's made the effort.

The fact that it's so neatly laid out is a contribution to safety in itself as any faults should be easier and quicker to find.

[Smoggy]

Looking good Mikeyboy, puts my rats nest to shame.

[mikeyboy1966]

Todays job,

removing obsolete wiring,

probably good timing as the insulation was really brittle and cracked in loads of places.

not good when it was running through uninsulated P clips bolted to the engine.

[mikeyboy1966]

I guess I’m rewiring the engine

 

[mikeyboy1966]

There’s a fair amount of redundant wiring so I’ll need to dissect the harness and work out what’s going on,so if anyone has a wiring diagram for a low line 4108 that would be great.

I’ve got my head around most of it but I’m stumped at this,so I’m missing the point somewhere.

the left cable goes to the main earth point on the starter motor body.

the right hand goes to redundant taped up wiring which would have been to the alternator,

why fuse the alternator earth?

given that it’s bolted to the engine.

seems odd as it only fuse I’ve found in the whole load/supply on the boat before it reaches the fuse board.

[mikeyboy1966]

The main loom connectors were so corroded I couldn’t separate them,

more drastic measures needed

[mikeyboy1966]

I’ve no idea what this did,

was bolted on but not connected,

there were however two bare wires hanging nearby.

[mikeyboy1966]

I’m thinking this is the hall sensor for the tachometer,

again I need to trace more wires and design a new wiring diagram and harness.

[Vaughan]

42 minutes ago, mikeyboy1966 said:

What you are looking at here , at bottom, is a 4TR alternator regulator, as well as a 6RA relay. These were necessary for the Lucas 11AC alternator, which most boats used in the late 60s. At bottom right looks like the remains of a starter solenoid.

 

33 minutes ago, mikeyboy1966 said:

 

This is a warning light unit, also needed for the 11AC alternator.

 

31 minutes ago, mikeyboy1966 said:

Perkins used to have a mechanical rev counter, cable driven from this position, connected to the camshaft.  This is a later adaption, for an electric rev counter.

With modern alternators, this is no longer necessary.

[Vaughan]

1 hour ago, mikeyboy1966 said:

This is a fast fuse. The top fuse is a spare.

This would have been the wiring arrangement before the boat was fitted with separate domestic batteries and a charge splitter.  In those days, everything was fed from the battery side terminal of the solenoid, which was usually mounted on a beam alongside the engine.  Unlike the BMC, the Perkins has a starter motor with a "Bendix" centrifugal pinion gear, so the solenoid is simply a relay from the key.  It is possible your engine has a more modern starter with a solenoid mounted on it.  This will also act as an electromagnet, to throw the pinion gear into mesh with the teeth on the flywheel.

In this case, the wiring is still the same.  The battery side terminal of the starter solenoid is the main feed for rest of the engine electrics. 

The negative cable from the battery is connected to the mounting bolt of the starter, simply because this is the best place to connect it to the engine.

[Vaughan]

9 hours ago, mikeyboy1966 said:

’m thinking this is the hall sensor for the tachometer,

again I need to trace more wires and design a new wiring diagram and harness.

This is effectively a small dynamo, driven by the camshaft, which feeds its own separate circuit to the rev counter. It is quite possible that this might still be working - if so, leave it alone!  All the same, it would be around 55 years old, by now.

Modern rev counters are sensed by a connection to the AL terminal of the alternator.

[Vaughan]

11 hours ago, Vaughan said:

This is a warning light unit, also needed for the 11AC alternator.

That's not strictly true - it is a flasher unit, the same as you have for the indicators in a car.  It was used to power a large amber light on the dashboard in parallel with the warning light and was probably also wired to a second oil pressure sender. There may have been a loud buzzer unit, also fed from that circuit.

Even so, hirers would totally ignore the warning and carry on merrily, until the engine blew up!

[mikeyboy1966]

Thanks Vaughan,

that all makes sense,I’ll take a better look at it all later.

[Vaughan]

On 28/12/2022 at 20:34, mikeyboy1966 said:

the left cable goes to the main earth point on the starter motor body.

This sets me thinking.

I have looked at your photos but there is not a clear view of the starter, although I can see a terminal on the side.  This may mean the starter is insulated from the engine.  Boats are almost always wired "earth return", which means the engine is used as the negative return for all the electrics, in the same way as a car.  "Insulated return" means that the body of the engine is kept separate from all the electrics, and all appliances or instruments have their own return, to a common bus bar and then to the battery. This is normally only done with steel hulled boats.

Before re-wiring the engine, you need to establish whether your boat is wired "earth return".  If the starter is an insulated type, that is no problem but you will need to make sure that the engine also has a substantial negative return cable, otherwise the alternator won't work and neither will any instruments.

[floydraser]

I wonder if any of that regulator is suitable for refurbishment? The square box marked "CAV" looks very much like something classic car/lorry/tractor enthusiasts may be looking for.

[mikeyboy1966]

Last visit between Christmas and new year,

ripping out old wiring and prepping for new install.

[mikeyboy1966]

Had a few hours at the boat today,

roughed out the support for the battery box.

[mikeyboy1966]

Out with the old,

pin with the new

[mikeyboy1966]

Seems a bit over the top for a few sockets and an immersion heater,

And  it’s in the way.

might need a rethink here

[mikeyboy1966]

Got a bit more done over the last few weekends,

new bulkheads to tidy things up,some plinths to run cables on.

new 220v cabling run in.

existing “factory “ wiring tidied up and secured

[BroadAmbition]

Nice one - Well done  

Griff