Max Negative

[mikeydpippin]

Any advise welcome,
On my 1957 G3 with Dynamo I am getting max negative showing on ammeter when lights switched on and engine running.
I have a charge of over 6v on Dynamo using multi meter as test explained by Matchless clueless, dependant on revs (joining Dynamo connections together and earthing with pos in terminal of Dynamo)
I have a dvr2 regulator.
When i put multi meter on battery I get 6.7v but when I connect multi meter pos probe to ammeter and black to earth I get -6.7v.
I have flashed Dynamo,
With engine not running and lights on I get halfway between neutral and max negative,with engine running and reasonable revs I get max negative.
I have a lot of learning to do regarding charging as all my 5 bikes drain the battery and therefore not able to go out in the dark.
Any pointers to websites, or flow charts that could help the novice would be most welcome.
Thanks in advance,
Mike

[DM2]

Looks like you have the battery and ammeter wired for pos earth.

Any chance that you are trying to use a neg earth regulator on a pos earth bike ?

[aobp11]

Is this a sudden defect or did you change components?
Albert

[mikeydpippin]

Thanks for the replies Gents,
The Dvr2 is def Pos Earth.
When testing the voltage at the Ammeter I had the red probe on the ammeter instead of touching earth, as the bikes positive earth so that explains the neg 6-7v DOH!!
With the engine running, if I wiggle the light switch the max neg happens every time all looks okay with the wiring, but will need to start again checking every wire is correct i have ordered a new switch, and a spare Ammeter just in case, from spares and will retry.
I will let you know outcome,
Always had a problem but as I rode bike only in daylight, didn't really do anything about it but now nights are drawing in I,m intending to sort them all out.
Thanks again.

[aobp11]

Hi Mike,
What is the problem, apart from what the ammeter is showing? Flat battery when the lights are on?
Apparently you still have the DC dynamo, but which type of ignition? If you have battery&ignition coil (in stead of a magneto) then that explains the heavier discharge current when the engine is running *and* the dynamo does nothing.
But it also seems that "during daylight" the dynamo current is more than the ignition current since otherwise you would not maintain the battery at 6.7 V. So that is with engine running but with lights off. Does the ammeter show a positive charge current under these circumstances? If so it's very strange that that the discharge current *increases* when you first switch on the lights and then start the engine. I'm not sure about the DVR2 connections but I suppose the output wire is connected to the ammeter and not to the switch. Anyway, when the ammeter shows zero or some discharge with lights off and running engine then I guess that you wired the DVR2 output to the ammeter but at the wrong side, that is at the same side as the battery wire. That way the ammeter will show the total current to the "consumers" (lights and ignition) but not the charge current of the battery.
Albert

[mikeydpippin]

Thanks Albert and sorry for the confusion,
I,vet bought a new regulator from Jampot spares and everything is working as it should, charging correctly.

I,m going to return the DVR2 regulator and see what happens.
Anyone else had the same problem?.
Will let you know.