DVR 2 correct installation

[Gavin]

Hi, I need to install a DVR 2 6v pos earth to my 51 A10 Plunger frame. I have included the wiring diagramme and the DVR 2 wring plan. As can be seen, this doen't look like a simple fix. when it comes to electricity i find that i am somewhat duller than Lucas and at times it feels that i am so dense light bends around me.

I am however pretty sure that I can connect Yellow to Yellow.
Green to Green.
Red either to earth or to red to go to Earth.

But, i am stuck on what to connect DVR 2 brown to...
and what to connect DVR 2 White to....that's beacuse the wiring loom ain't got a brown A I have got a 6v positive earth bike

So can someone tell me in simple terms what the correct connections will be please?

[RogerSB]

Hope it helps - Note white cable for 6V.

[groily]

Yup, red to earth on positive DVR2s.

Your 'A' is purple from the schematic - so connect A, the Brown from Regulator, to that. 'A' goes to the Ammeter, same side as the other purple wire which powers the light switch at terminal 3.

Your brown lead in the new loom goes off the other side of the ammeter, to battery Negative - and that's fine.

For 6v, splice the brown and white together off the regulator. On the printed sticker panel on the regulator it should say 'leave  white disconnected and insulated for 12v' or words to that effect.

Fuses maybe? Original diagrams didn't include - but I think most people would. Minimum of one off the battery - and if the brake light and horn are not wired through the ammeter, I'd be sure they were covered by at least the main fuse as they are quite common causes of grief.

Roger beat me to it! Note he has a fuse  . . .!

Good luck

[Gavin]

Thanks Roger and Groily. That's perfectly clear to me now. Just have to put a seat on tomorrow and add a fuel tank, then i can see how it all goes. Will report back in a couple of days.

[KiwiGF]

Thanks Roger and Groily. That's perfectly clear to me now. Just have to put a seat on tomorrow and add a fuel tank, then i can see how it all goes. Will report back in a couple of days.

Its important to measure the field coil resistance to make sure its within spec, if its too low there is a risk of damaging the dvr2. I suspect the dvr2’s are prone to trying to give too much current to a duff field coil in attempt to (still) give a decent charge to the battery, and in doing so damage their internal components.

The instructions give the spec for the field coil, but its around 3 ohms from memory.

[groily]

Other NotesThe resistance of the dynamo field winding must be greater than 2.5 ohms. If less the dynamo will be very inefficient and there is a real risk of damaging the regulator

Quoted from the DVR tech spec sheet.

Standard 6v Lucas E3L field is just under 3 usually, 2.8 seems to be about the norm (- more on '12v' finer windings of couse).
Always good to check as Kiwi GF says, and make darn sure the wire tails are in good condition where they emerge at the brush end of the dyn.