Alternator wiring - installing a diode splitter

kingfisher

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This is the back of my alternator. Taking a digital picture is a good way of getting a solid view of the back of that jumble of cables, which the previous owner was kind enough to spray paint green.
wiring2.jpg


Currently the red (+) goes from the battery to the starter motor, where the red(+) from the alternator is attached to the same pin.

I want to install a diode splitter. So the red from the battery stays on the starter motor, the red from the alternator goes to the diode.

But where is the sense wire? And what is "W" and what is "D+" ?
 

VicS

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You'll find some useful info on This site


The red from the alternator will go to the common connection on the diode splitter instead of the starter. One of the outputs of the splitter will go to the starter battery the other will go to the domestic services battery.

You will probably have to get the alternator modified to make it battery sensed then the sensing connection will go to one or other of the batteries. The link above discusses the merits of one battery over the other. Some splitters have a connection for the sensing though.

W is an un rectified ouput for a tacho.
 
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Much easier is to talk to someone like KDDPower on here and fit a VSR system ... then no need to fiddle with sense and upping the charge voltage etc.

I have a split diode still fitted in my engine bay - ballast !! Gave up with it.
 

pvb

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Easy answers first - W is the tachometer connection, and D+ is the warning lamp connection.

The alternator on your Volvo Penta 2010 was probably equipped with a battery sensing connection. It would be a yellow wire, and if it isn't connected anywhere else, you should find it connected to the B+ terminal. Disconnect it, join it to a longer length of cable (about 1.5 sq mm) and connect the other end to the positive terminal of your domestic battery.

If you haven't already bought a diode splitter, you could consider a VSR (voltage sensitive relay) instead, as sbc suggested. If you fit a VSR, connect the alternator output to your engine start battery, then let the VSR link the start battery to the domestic battery.

If you have already bought a diode splitter, it will work fine with the alternator sensing lead connected.
 

FullCircle

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You have an N type alternator. Here is a link to the AMS Merlin info which gives good diagrams for the pin outs, if you ignore the ALS regulator, which I recommend, as well as installing the VSR system. Top it off with a DCM600 battery power management indicator. Its very good, and worth the money.

Alternator info
 
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