Tacho wiring - VP D2-55 part 873686

[Alex_Blackwood]

Thanks Paul.

Excuse me sticking snout in, However, surely if the Tacho. is designed for "W" connection all that is required is a wire from the "W" terminal ands the internal tacho. wiring sorts out the rest?

 

[Tintin]

Excuse me sticking snout in, However, surely if the Tacho. is designed for "W" connection all that is required is a wire from the "W" terminal ands the internal tacho. wiring sorts out the rest?

Having owned boats for decades, and rewired most, or at least stripped out wiring bodges, I take the view that the Volvo engineers had a reason for using a flywheel sensor, rather than the W connection. Or it could be specified by Alubat, the Ovni builders, who know their stuff when it comes to electrics and aluminium boats.

Either way, changing that scenario against such knowledge, to effect a quick fix, is alien to me.

Electrolysis and aluminium boats is a tough subject. On GRP boats the engine is usually bonded to -ve, as is the starter and alternator. This is not the case with Ovnis, where the starter has a solenoid to bond to -ve until starter, and the alternator has isolated too.

I hope that helps in understanding my quandary.

Basically it is this - do I stump up over £300 for the Volvo replacement,or go with an £85 alternative that means I have to alter the core wiring away from how it was originally done.

I'm going to give the cheaper a go, and check current leakage with my silver anode.

 

[Alex_Blackwood]

Having owned boats for decades, and rewired most, or at least stripped out wiring bodges, I take the view that the Volvo engineers had a reason for using a flywheel sensor, rather than the W connection. Or it could be specified by Alubat, the Ovni builders, who know their stuff when it comes to electrics and aluminium boats.

Either way, changing that scenario against such knowledge, to effect a quick fix, is alien to me.

Electrolysis and aluminium boats is a tough subject. On GRP boats the engine is usually bonded to -ve, as is the starter and alternator. This is not the case with Ovnis, where the starter has a solenoid to bond to -ve until starter, and the alternator has isolated too.

I hope that helps in understanding my quandary.

Basically it is this - do I stump up over £300 for the Volvo replacement,or go with an £85 alternative that means I have to alter the core wiring away from how it was originally done.

I'm going to give the cheaper a go, and check current leakage with my silver anode.

I think that Paul has already, adequately, explained that using the "W" terminal will make no difference to any of the existing -ve wiring. Or any other existing wiring for that matter!

 

[PaulRainbow]

Having owned boats for decades, and rewired most, or at least stripped out wiring bodges, I take the view that the Volvo engineers had a reason for using a flywheel sensor, rather than the W connection.

Volvo don't make the D series, they only do the marinising bits.

Or it could be specified by Alubat, the Ovni builders, who know their stuff when it comes to electrics and aluminium boats.

That's not realistic, adding the sensor after manufacture would be virtually impossible.

Either way, changing that scenario against such knowledge, to effect a quick fix, is alien to me.

Electrolysis and aluminium boats is a tough subject. On GRP boats the engine is usually bonded to -ve, as is the starter and alternator. This is not the case with Ovnis, where the starter has a solenoid to bond to -ve until starter, and the alternator has isolated too.

So what ? My boat is GRP and the starter and alternators are both -VE isolated, not even a relay, they are properly isolated.

I hope that helps in understanding my quandary.

Basically it is this - do I stump up over £300 for the Volvo replacement,or go with an £85 alternative that means I have to alter the core wiring away from how it was originally done.

It's not "core wiring", it's just the tach sensor connecting, which is fully insulated from the hull anyway and the existing isolation isn't affected at all, you use the same wires.

I'm going to give the cheaper a go, and check current leakage with my silver anode.

I've said this too many times now, so il'll leave this thread alone.

 

[Tintin]

I think that Paul has already, adequately, explained that using the "W" terminal will make no difference to any of the existing -ve wiring. Or any other existing wiring for that matter!

Yes, but I was responding to your post, and explaining why I was asking the question.

 

[Tintin]

Volvo don't make the D series, they only do the marinising bits.

That's not realistic, adding the sensor after manufacture would be virtually impossible.

So what ? My boat is GRP and the starter and alternators are both -VE isolated, not even a relay, they are properly isolated.

It's not "core wiring", it's just the tach sensor connecting, which is fully insulated from the hull anyway and the existing isolation isn't affected at all, you use the same wires.

I've said this too many times now, so il'll leave this thread alone.

I was replying to Alex's post Paul. Not questioning your thoughts or experiences.