Not been here for ages, been enjoying BSA life and fun. This coming August my Army bike will be doing convoy duties to the BSA Rally in the Cotswolds, thing is I've a strange charging problem. Starting the bike from cold, the Amp meter shows a healthy charge, ride for about 7 miles and it drops to zero..? Put the lights on and it shows a discharge, if I put the lights on when it's showing a charge, it'll go to just over the zero, as it should. could it be as simple as a new set of brushes..? All I know about electrics is DON'T let the smoke out of the wires...!
It should show a charge when you run the bike initially if the battery is down...This will slowly reduce as the battery is bought up to fully charged..When you turn the lights on it will probably show a momentary discharge until the regulator kicks in and brings in the the dynamo to once again balance the load on the system...
It seems that if while you are showing a charge and you turn on the lights the charge stays on and balances the load..
However, if the battery is fully charged and then when you put the lights on the system is not 'cutting in' correctly that would be a regulator fault...
It is possible to get an erratic charge from the dynamo if the magdyno clutch is slipping, so first I would check the dynamo output a couple of times to see what it's producing...
Also, always ensure that your battery is in good condition..If it is not and it is thus not holding a charge correctly, the dynamo will be overworking in a vain attempt to charge it up...That can lead to dynamo overheating/damage as the system is not designed for the dynamo to run continuously..Ian
I have found that if the seal that stops oil from entering the dynamo is worn oil can enter the magdyno clutch area. When a load is put on the dynamo eg when the lights are switched on the clutch will slip. I had the same problem a few years ago.
Don't know how many hundreds of times people have needed to be reminded that in a REGULATED charging system, the generator only generates when it is needed.
As Ian has rightly mentioned if the battery does not need to be charged, the amp meter will show 0 cause the regulator has not turned the charging system on.
Trevor, indeed I do understand that, BUT. The Amp meter shows a healthy charge for around 7 miles, then it drops to 0 if I turn the lights on, it'll show a discharge. And the battery goes flat, if I put the lights on when it's showing a charge all is well until the engine is shut off...
I'm now suspecting the regulator, being a tad busy I'll have to sort that out when I gets around to it....
