Until recently my dynamo charging has been fine. My dynamo failed(worn brush and bearings), so I have exchanged it for another one. While looking for the fault I also tried another regulator, but swapped back to the known good one after fixing it.
trouble now, is the system does not charge up the battery sufficiently. I have put a volt meter on the circuit, and on start up, it runs fine -volts up to 14volts. After about 5 minutes of driving, the volts drop, and presumably it does not charge(although the ignition light stays on).
Any thoughts -a weak dynamo field, or faulty regulator?
And before you ask i am trying to resist the call for an alternator, as the dynamo system has served me well for the last 15 years
Dynamo stops charging after n5 minutes
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Re: Dynamo stops charging after n5 minutes
How far do the volts drop? There is some temperature compensation built into the regulator.. You will always get an initial surge of charge and then it tapers off to almost zero as the battery comes up. You say the light stays ON - does it go OFF initially - and then it comes ON ?? And that's when the volts drop ?? Am I reading this correctly??
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mowogg
- Minor Fan
- Posts: 410
- Joined: Mon Oct 22, 2007 9:45 pm
- Location: Chichester West Sussex
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Re: Dynamo stops charging after n5 minutes
Sorry -I have just reread my earlier post.
The light works as would be expected -is on when your turn on the ignition and start up, and then goes off when running (flickering at slow idle).
The voltage drops below 13 volts after about 5 minutes, having been above this before then. It can be as low as 11.5 with everything running (lights, heater etc). The lights appear to brighten on revving, but the battery seems to discharge. This is not going flat due to slow traffic -this when driven at 50-60mph.
The dynamo is a second hand one, but looks ok. I put new brushes into it, and checked it over.
I am guessing one of the two components are letting me down?
The light works as would be expected -is on when your turn on the ignition and start up, and then goes off when running (flickering at slow idle).
The voltage drops below 13 volts after about 5 minutes, having been above this before then. It can be as low as 11.5 with everything running (lights, heater etc). The lights appear to brighten on revving, but the battery seems to discharge. This is not going flat due to slow traffic -this when driven at 50-60mph.
The dynamo is a second hand one, but looks ok. I put new brushes into it, and checked it over.
I am guessing one of the two components are letting me down?
Re: Dynamo stops charging after n5 minutes
I suspect the regulator needs setting up. I suggest you try the other regulator again. Simple test for dynamo output is to join the two terminals together and run it at revs, measure the voltage - switch on everything you have and measure the volts again. Don't leave the terminals joined....... although on my rally Minor I had a switch that did just that - for max output when running all my lights etc...... It never did the dynamo any harm. But if you run like that for any length of time without everything switched on - it will 'fry' the battery.......