Magneto or Coil ignition

[mikeydpippin]

Would that cause the problem Chris, maybe I will try another tomorrow 👍

[spookefoote1956]

Am I right that the battery isn't charging and that you've got a sound battery?

[mikeydpippin]

Correct

[spookefoote1956]

I use a DVR2. It's the canine's sphericals.

[spookefoote1956]

If your wiring, dynamo and battery are sound then it points towards the regulator / rectifier.

[Greybeard]

I use a DVR2. It's the canine's sphericals.

No good with mikeydpippin's alternator though. DVRs are for dynamos.
If there's no volts showing with the engine running it sounds to me like the rectifier isn't working so that the alternating positive/negative output balances out at zero. You could try testing it with a multimeter set to measure AC -alternating current. The battery moniitor will only detect DC
I'd suggest you give Alan Osborn a call at http://www.aoservices.co.uk/index.htm
He is extremely knowledgeable and helpful. He was able to identify the problem I had with the alternator on my G80 and with one of his A-reg regulator/rectifiers fitted it has been working perfectly for some years now.

Steve

[spookefoote1956]

See what you're saying Steve. Would a Boyer Powerbox be any use?

[SPRIDDLER]

Oh well tried but failed, connected the voltage readout to coil and earthed the other cable and it showed the battery voltage, started bike and voltage shows zero whilst engine running.

You may have a charging fault (AC - DC rectifier?) which was the reason for your previous flat battery problem.
Does the headlight brighten and dim significantly as the revs rise and fall?
Does the unit show 'zero' i.e 0.00 or does the display disappear completely?
I wonder if a fault (in the rectifier, switchgear or wiring?) is causing the unit to read zero when you turn on the ignition to run the engine but doesn't show up when the ignition is Off, which is when you get a reading on the unit - but I can't think why the unit would go to zero when the engine is started (Ignition switch turned On) when the unit is connected direct to the battery as it should at least continue to read the battery voltage.

LATER EDIT...

If there's no volts showing with the engine running it sounds to me like the rectifier isn't working so that the alternating positive/negative output balances out at zero.

Ah, maybe that's why the unit shoes zero even when connected direct to battery. (Alternators are a bit too modern for me )

[Greybeard]

See what you're saying Steve. Would a Boyer Powerbox be any use?

They do a range that includes alternator specific ones. I've heard that they have a good reputation but I've no experience of them. I don't know what they're like at giving help/advice with problems either, but I do know that Alan at AO Services is first rate in that regard.

Steve

[Groily]

A Boyer unit would be good, yes. It also contains a capacitor which enables battery-less starting and running in principle.
Another very good unit is the Podtronics one.
However, these two are more expensive than the AO unit, which does an excellent job too.
I use the A Reg 1 (and also the A Reg 6 for 6v applications) regularly and have never had a problem with one.
All of these units for single phase alternators enable considerable simplification to the wiring if converting from the original three-wire type alternator stator with complicated switches. (But you may end up without Emergency Ignition as an option, except with the Powerbox, which provides it in a different way.)