Alternator Wiring

[colhel]

I really need to look at tidying up my alternator wiring and now the heat exchangers off I've got reasonable access. The engine is a Tamd41a squeezed into hole just big enough for it to fit into and the alternator is tucked away beneath the heat exchanger.
There' a Sterling regulator fitted, but I'm sure it's not working or even wired up correctly but until our last trip out a few weeks, everything worked fine so I didn't feel inclined to mess with it. But now, I'm getting the charge and temp warning lights staying on and volt meter on the dash staying st 12v even with revs on the engine.
The yellow wire which feeds back from the batteries was fused but when i checked the connection, it just crumbled in my hand, so that could be the problem but I'd like to understand further whats going on.

So a couple of questions to get me started.
On this pic of the alternator there's a black wire coming out, from what looks like the regulator, but atm isn't connected to anything. There's a spade connector on the end. Any ideas what this does as my internet searching has drawn a blank.



I'm sure the component shown below is a split charge diode but very little info on the net. The writing is "paris rhone distributeur". Can anyone offer any info?



Cheers!

 

[PaulRainbow]

The black wire could be for an external regulator or some such.

Pic two is the regulator. My bad, should have looked closer. It is the split charge diode, as VP says in post #4.

 

[Plum]

I really need to look at tidying up my alternator wiring and now the heat exchangers off I've got reasonable access. The engine is a Tamd41a squeezed into hole just big enough for it to fit into and the alternator is tucked away beneath the heat exchanger.
There' a Sterling regulator fitted, but I'm sure it's not working or even wired up correctly but until our last trip out a few weeks, everything worked fine so I didn't feel inclined to mess with it. But now, I'm getting the charge and temp warning lights staying on and volt meter on the dash staying st 12v even with revs on the engine.
The yellow wire which feeds back from the batteries was fused but when i checked the connection, it just crumbled in my hand, so that could be the problem but I'd like to understand further whats going on.

So a couple of questions to get me started.
On this pic of the alternator there's a black wire coming out, from what looks like the regulator, but atm isn't connected to anything. There's a spade connector on the end. Any ideas what this does as my internet searching has drawn a blank.

I'm sure the component shown below is a split charge diode but very little info on the net. The writing is "paris rhone distributeur". Can anyone offer any info?
Cheers!

The join in that yellow wire does not look good!

www.solocoastalsailing.co.uk

 

[volvopaul]

Black is earth or battery negative on the standard loom you will find a thick black that is earth return to the block from the alternator negative terminal , has 8mm securing nut. There is also a smaller gauge black that’s the engine negative loom that is earth return for some of the sender like oil pressure and oil light warning .
The grey is the Rev counter feed has a 7mm nut .
Red is positive, battery plus 10mm nut .
Now by the looks of it you have a separate diode splitter , don’t throw that away as that type is obsolete now , you have to buy a later type splitter if it’s failed . There will be another Red positive output to another bank of batteries .
Lastly the yellow wire is battery sensing , without that having a positive feed the alternator won’t give out any charge so check it for current , it should be fused 7.5 amp at the battery end .
It’s all basic boat set up as I’ve described for that era of engine .

 

[colhel]

The black wire could be for an external regulator or some such.

Pic two is the regulator. My bad, should have looked closer. It is the split charge diode, as VP says in post #4.

Thanks for the confirmation, I wondered if it was a regulator at first aswell.

The join in that yellow wire does not look good!

www.solocoastalsailing.co.uk

There was a joint which disintegrated so I just wound them together temporarily. One of the reasons I want to start again.

 

[colhel]

Black is earth or battery negative on the standard loom you will find a thick black that is earth return to the block from the alternator negative terminal , has 8mm securing nut. There is also a smaller gauge black that’s the engine negative loom that is earth return for some of the sender like oil pressure and oil light warning .
The grey is the Rev counter feed has a 7mm nut .
Red is positive, battery plus 10mm nut .
Now by the looks of it you have a separate diode splitter , don’t throw that away as that type is obsolete now , you have to buy a later type splitter if it’s failed . There will be another Red positive output to another bank of batteries .
Lastly the yellow wire is battery sensing , without that having a positive feed the alternator won’t give out any charge so check it for current , it should be fused 7.5 amp at the battery end .
It’s all basic boat set up as I’ve described for that era of engine .

Thanks Paul, that's a great write up. I'll print it off so I can refer too it next time I'm down

 

[volvopaul]

Thanks Paul, that's a great write up. I'll print it off so I can refer too it next time I'm down

The extra diode block used to be sold as a part from Volvo but they stopped making that design .

 

[colhel]

The extra diode block used to be sold as a part from Volvo but they stopped making that design .

Hopefully that bit's okay then. I think I'm on a hiding to nothing until I renew some of the wiring from the alternator. I'll take some more photos next time as there's a couple more bits that I'd like identified ie, next to the diode block there's small electrical component(possibly relay) with a push button on top.
Anyway, you've been really helpful ?