FAQ for the V-Reg Dynamo regulator
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after fitting the V-Reg you have a problem, following these notes
should have the unit working. The V-Reg has been designed thoroughly
and is very tough so most problems will be with the dynamo or wiring.
First make sure you have done Polarising and Testing as detailed in the
Fitting Instructions, as in a lot of cases this will clear the fault.
No Charge: My dynamo/regulator doesn't charge the battery?
Despite the ammeter not deflecting to
the charge side it may actually be charging. First check for a charge
voltage at the battery as per the Fitting Instructions for the V-Reg.
If this voltage is correct then it is most likely that the Ammeter has
been miss wired. There are basically 3 circuits at the Ammeter:
- The Charge - from the Regulator (A wire).
- Discharge - lights (sometimes ignition).
- Battery. The wire to the battery must always be on its
own. If the charge from V-Reg "A" terminal is connected straight
to the Battery connection, you will be seeing the discharge but
NOT the charge.
The dynamo might be reverse polarised --- Repolarise.
The battery might be flat --- the V-Reg must be used with a well
charged battery (unlike the original electro/mechanical regulators).
D and F reversal within the dynamo. --- this fault can cause many
effects, no charge, over charging or even damage to the regulator.
Battery: It is a new battery!
This does NOT mean that it is fully
charged. A 'New' battery can be flat very quickly if left discharging
(lights on or wrong connections). There have been cases of faulty from
'new', eg filled with water only.
Battery: I have just charged the battery.
Often there is a reliance on the
trickle charge 'Optimate' type of charger to properly charge the
battery. A; If the battery was really flat it might take several days
to fully recharge, B; A well flat battery often will not charge
properly at all from such a charger. Please use a normal charger that
says it is giving a couple of amps and charge for a few hours at least.
Blown Fuse: When connecting
the battery the fuse blows or there is a buzzing from the dynamo or
there is a small spark and/or the battery goes flat in a few hours.
All of these 'faults' can be caused by
a reversed battery or Regulator ie you have a regulator of the wrong
polarity that you are trying to use. Also it is not unknown for a
battery to be reverse charged! Hence every thing looks correct but it
is NOT. Check battery polarity with a multimeter.
Discharge: At tickover the bike shows a small discharge,
This is correct, the V-Reg gets its Field current from the battery, which then shows on the Ammeter.
Overcharging: The Ammeter shows overcharging!
A prime reason for this is that the
dynamo has an internal short between D and F. (or a similar wiring
fault on the bike) such that the regulator is in effect out of circuit,
not regulating. Once this fault is fixed, the Regulator should function
Testing: Testing the Regulator.
No meaningful tests can be done with a
multimeter on ohms. If after having checked all of these points you
still have a problem then we are happy to test the V-Reg. After
returning it with return postage.
Polarity?: What factors affects the polarity I use?
There is no strict rule nor technical
reason, except that the electronic regulator IS polarity conscious,
therefore once you have chosen a specific polarity regulator you are
Some points to bear in mind if you are undecided:
Digital Multimeter: These can have an unsettled display, due to being by affected by
ignition interference. Try another meter preferable an analogue (pointer type).
- What polarity do you expect? (Just about all BSA came out of the factory with positive earth.)
- Also think about the next owner of the bike-hence keeping it original might be a good idea.
- What colour is your earth wire? Red is Positive earth. Black is
Negative earth. This might sound obvious but there is a lot of
'casual' wiring out there which eventually leads to confusion/damage.
- What polarity do you expect on your bikes? ie If you have many
bikes keeping them all the same can save further
confusion/damage.('till you sell it!)
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23 October, 2009