Help with identifying part

[pjbori]

Hi there,

I just embarked on a full rewiring project after examining the state of the onboard electrics after my first season and first boat ever. I'm going slowly, drawing up the diagram as I go, making sure I get a complete overview of all systems before touching it. Today I made it to the engine and noticed that this part - which seems pretty crucial as it is directly connected to the starter - is in a pretty bad shape. I guess it needs replacing, but I'm not sure what it is, can someone help me out (pic attached)?

I know this will be a pretty obvious answer, but remember, first boat, first time touching electrics, so please forgive my naïveté

Thanks!

[Spot]

Hello PJ,
It looks like a relay. To get the best answers for this question, make and model of engine and also of the boat are very helpful, along with approx. location. Someone might come up with a wiring schematic, parts supply source, etc. and then you are in good business.

Hard to see where all the wires go, any chance for a more squared-up picture?

[GordMay]

"Directly connected to starter", I'd guess starting solenoid/relay.

[stormalong]

It looks like an ancient voltage regulator. How old is the boat? Was there a cover over it?

[Dogscout]

I agree on Relay, especially since that appears to be a more modern one next to it.

[Emmalina]

I would go with heavy solenoid but certainly not a marine (sealed) unit Windlass maybe

[Lepke]

Looks similar to a voltage regulator I had with a WWII 32v aircraft generator.

[mjscottinnc]

The largest wire size in the picture would seem to preclude it from being a starter solenoid, if you look closely at the relay armature it has both a small diameter wire winding which is covered and a large diameter winding (shinny copper wire). I’d be betting on a generator or alternator control, the dual coils suggest current control, but voltage control is equally as likely.

[LittleWing77]

Originally Posted by Lepke

Looks similar to a voltage regulator I had with a WWII 32v aircraft generator.

In case anyone missed it, this is Lekpe telling a joke.

Geeze, Lepke - You're always so straightforward and no-BS, I almost missed it myself!

In answer to the OP's question, if it is a starter solenoid, get rid of it. Look at the corrosion on that blue connection. I can see why you're rewiring the boat.

You are using marine wiring techniques and materials, correct?

Fair winds,
LittleWing77

[pjbori]

Thank you everyone for the responses! I wasn't sure whether @Lepke was being ironic, but I sure get why he would be - the poor thing looks pretty weathered. I'm thinking it might be a dynastart, which (from another forum post) is 'a DC generator that also doubles as the starter motor'. The engine in the post is a Volvo Penta MD6A, same as mine (mine from 1976), so it could fit the profile. Anyone have experience with this?

@stormalong, yes there was a tin box over it

@Spot, model and make above, the location is Zealand in Denmark, Scandinavia.

@Dogscout there is indeed another thing next to it, from Bosch, however I don't have a picture to share yet - will go to the boat in a day or two and take some proper photos that includes that too.

In the meantime, a few more pics of the same thing, different angle. Thanks everyone, really appreciate the input...

[Wotname]

Dynastart

Quite possibility. Is the engine fitted with a dynastart unit? Typically a dynastart uses V belt off an external flywheel to start the engine and then becomes a generator after starting. Sometimes a PO will fit an aftermarket alternator and will dispense with the generator aspects of the dynastart while retaining the starting aspects.

As others have stated, it does look like a old time voltage regulator which typically utilises a reverse current coil (relay) and a vibrating voltage control relay. The statement that it was connected to the starter motor confounded the problem as there would be no need to have a voltage regulator connected to a starter motor.

BUT...there would be plenty of reasons to have a old style mechanical voltage regulator connected to a dynastart.

So if the engine does have a dynastart (even if only for the starting aspects), then the mystery item could be a mechanical voltage regulator.

[flightlead404]

Originally Posted by LittleWing77

In case anyone missed it, this is Lekpe telling a joke.

Geeze, Lepke - You're always so straightforward and no-BS, I almost missed it myself!

In answer to the OP's question, if it is a starter solenoid, get rid of it. Look at the corrosion on that blue connection. I can see why you're rewiring the boat.

You are using marine wiring techniques and materials, correct?

Fair winds,
LittleWing77

It looks like a common old Ford/Delco etc voltage regulator from the ancient times before semiconductors lol. So 30's for automotive technology, 80's if its on an aircraft.

[Wotname]

Originally Posted by Lepke

Looks similar to a voltage regulator I had with a WWII 32v aircraft generator.

Originally Posted by LittleWing77

In case anyone missed it, this is Lekpe telling a joke.

Geeze, Lepke - You're always so straightforward and no-BS, I almost missed it myself!

..................

If it was a joke, it went over my head as well .

I did think it was (maybe) tongue in cheek but wasn't sure. Some vintage aircraft do have mechanical (relay type) voltage regulators and do have generators. Some might have 32 volt systems although I have never seen one. Lekpe is of an age that allows him to have enough experience that would recall these things yet also intelligent enough to make a good yarn seem true.

FWIW, many small modern jet engines use a gear / shaft driven dynastart arrangement (starter/generator combined unit).

So... please do tell Lekpe

[sailor_ed]

Sure looks like a voltage regulator to me. My Atomic 4 had one and I could have sworn that they were used with charging "generators" and alternators too in the days of yore.


Fair winds
Ed


(Hey, am I really THAT old!?)

[adjo]

External voltage regulator.