Wiring a Denso alternator in place of a Lucas

[GT6MK3]

G'Day all,

I've bought and physically fitted a little Nippon Denso, but am stuck trying to figure exactly how to wire it in.  



The ND has three terminals, the (fuzzy) bolt for a ring terminal, the and the "T" terminal with an "upright" and a "crossbar"



Westfield-world.com suggests I wire it thusly...



triumphspitfire.com shows how the original wiring (probably) should be.



This is the old connector



Three wires.  Little brown, Big brown, and Brown Yellow.


Trawling the net suggests I need to add another wire "to ignition".


Anyone able to concisely explain what wire to hook where, and what to add to where?



Thanks in advance


Craig

[Nick Moore]

Craig,
I ran the 'live feed' wire to the positive side of my coil, so that it sees a voltage when the ignition key is turned. The warning lamp wire was kept as it had been with the Lucas alternator. The main output cable is attached to a screw-on post, and that lead runs to the solenoid, linking to the main lead to the positive side of the battery.

Nick

[willcolumbine]

There are various different types of Nippon Denso alternator.

The big live terminal is generally pretty easy to ID! You need to run the two live brown wires to that. The other connectors vary slightly depending on the alternators original application.

On yours it looks like you've only got two. One of these will be for the ignition light - that's the other wire on the standard connector. The other is for an ignition switched supply. I picked mine up from the coil because I've chucked out the ballast resistor wire but if your car has it, you'll need to find a white cable upwind of the resistor wire.

Some types of these alternators have only the one connector - for the ignition switched supply (no light).  Some, like mine, have a 'Sense' terminal too. On the original application this supplies info to an ECU and so isn't required on our cars!

[junkuser]

According to the wiring diagram the large brown wire would go to the ring terminal
the small brown to terminal 2 and the brown/yellow to terminal 1.
To check the wires at "This is the old connector" have not been changed you could use a 12V lamp.
The large brown should illuminate the lamp fully at all times.
The small brown should give the same only with the ignition ON.
The brown/yellow should give a duller or no illumination with the ignition ON depending on the wattage of the test lamp. The ignition lamp will light up if the test lamp wattage is high enough and fully if this wire is put to frame with the ignition ON.
"Trawling the net suggests I need to add another wire "to ignition"."
Not on this model of Denso.

[willcolumbine]

Both those brown wires are live, unswitched and unfused! If you trace them back from the alternator they go back to the positive terminal on the starter solenoid - which is wired straight to the battery. On my car they both go direct to the positive battery terminal.

In fact, if I recall correctly, if you study them closely you'll see that the terminals for the little brown and big brown wires are actually connected!

Lord knows why triumph did it this way. Maybe it was cheaper to use a big cable and a small cable that they'd have in stock anyway than to order in much fatter cable specially for this application?

[junkuser]

Yes Will, I misinterpreted the Triumph wiring diagram.  Saw what I was expecting rather than what was there.  Both being brown should have switched me on.
Does sound as though a switched positive is required to comply with the Denso wiring diagram.
I wonder why Triumph wired it this way also.
Thank you for pointing this out.