Whats going on?

mikeydpippin · Post by **mikeydpippin** » Sun Mar 20, 2011 6:38 pm

Took my G3 out today (beatifull day)all going well but noticed no horn and no lights continued and suddenly amp meter started to show max pointing to positive almost off the scale and lights and horn worked,so turned lights on and the amp needle went back to the middle of the scale.The needle then went to negative,so turned lights off.This continued throughout the journey,one way then tother.Got home switched off engine and negative showing on amp needle.no lights and no horn so removed the side cover.Control box (regulator)smelling of burnt plastic and battery flat.Is this reversed polarization,or control box knacked?.
Thanks in advance.Edited by - mikeydpippin on 20 Mar 2011 6:54:09 PM

SideValve · Post by **SideValve** » Sun Mar 20, 2011 7:59 pm

Dead regulator sounds most likely. If its a proper one you might be able to fix it if its just sticking or something is shorting. If its a solid state jobby its time to throw it away and buy another.
Worth checking the rest of your wiring to make sure nothing got toasted.

Groily · Post by **Groily** » Sun Mar 20, 2011 9:49 pm

Dynamo G3 I'm assuming?
Unlikely the polarity reversed itself as you were going along, but v likely the regulator started playing up, I agree. If it smells of burnt plastic . . . . time to replace it I'd say. Might be fixable/bodgeable, but would you trust it again? Were I in your shoes, I'd want to check over everything as Peter said, especially the dynamo, to be quite sure the current surge that prompted your off the scale Plus reading didn't do any harm through overloading, nor that the off the scale Minus readings didn't hurt the armature by shoving the battery up it. With any luck no harm done, but worth a health check I'd say.
Not everyone's choice I know and respect, but if replacing the regulator I'd go electronic every time.

mikeydpippin · Post by **mikeydpippin** » Tue Mar 22, 2011 7:22 pm

Thanks guys to update i have fitted a DVR2 electronic regulator and now the ammeter rises to maximum positive as the throttle is fully opened.and reverts back to normal (middle setting)when throttle backed off.
Any ideas,yes G3 Dynamo 6v,positive earth battery and DVR2 electronic regulator.

Groily · Post by **Groily** » Tue Mar 22, 2011 8:05 pm

The DVR2 is a new fitment then, in place of an old mechanical regulator?
If all things are equal, there should be a charge of not more than 2A (or so), with lights on or off and it should settle as the revs rise, not go up to max on the ammeter. But sometilmes things aren't equal. What sort of battery are you running? Sometimes, with Cyclon cells and things of that ilk which have very low internal resistance, the charge rate will soar when the cells are pretty flat, even with a DVR2 or equivalent. If the battery has taken a hammering with the old regulator failing and all that, I'd say it would be worth giving it a decent trickle charge to get it back to normal, and then see what the ammeter says.
Some of this applies just as much to a lead acid battery that is on its last legs!Edited by - Groily on 22 Mar 2011 8:10:56 PM

mikeydpippin · Post by **mikeydpippin** » Tue Mar 22, 2011 8:09 pm

Yes Bill,I have replaced the old mechanical regulator with the DVR2 electronic regulator.I left the relatively new battery on a trickle charge overnight.Edited by - mikeydpippin on 22 Mar 2011 8:13:34 PM

Groily · Post by **Groily** » Tue Mar 22, 2011 10:02 pm

OK. So with a decent, newish, charged battery, the thing is still not regulating properly although it seems it's cutting in (and out?) correctly.
The ammeter needle ought to settle at a modest charge, which it should reach by, say, 2000rpm and then maintain regardless of rpm. The charge should definitley not go on climbing with higher revs. An amp or two would be the normal at mid rpm+ even with a slightly discharged battery. At tickover, the ammeter should read zero with magneto ignition, unless the lights are on, when there will be a discharge.
I'd be surprised if the DVR2 is faulty right out of the box, but nothing is impossible I suppose. I assume all 5 wires are connected, with the pair that needs to be doubled up for 6v operation doubled up as per the instructions.

If all that is OK, are you confident all your earths are good? - and the switch and ammeter connections themselves? - I wondered about them in your initial post because of the sudden lack of horn and lights. They should have worked off the battery, even if the dynamo was not connected properly due to a regulator fault. Simplest fault that would account for that would be a bad battery earth lead, bad negative lead to switch or ammeter, or a problem with a bullet connector somewhere between - or fuse holder if you have one fitted.

If that all checks out OK, things get harder.
What is clear though is that the dynamo works.
The symptoms you speak of suggest the armature's full output (D) is being permanently fed to the field coil (F) when the electronic cut-out is closed, which is what regulators, of any sort, are supposed to limit! Running at high revs with the field not regulated will eventually (or sooner) burn out the armature and/or damage the battery, so it's a problem that needs solving obviously. It's almost as if there were a short between D and F at the dynamo, which I'd have thought very improbable!

mikeydpippin · Post by **mikeydpippin** » Fri Mar 25, 2011 9:05 pm

Bill,Many thanks.
I have returned the DVR2 to Dynamo Regulators and the DVR2 had a fault not sure why, but the company albeit confused why this happened (as all regulators are checked before despatch)have decided to send a replacement.
As always an answer to a problem could be helpfull to the next member.
Thanks again Bill.