I thought I had sorted the problem.

After cleaning and flashing the dynamo, it put out around 8 volts at just over tick over.

Went to start the bike a few hours later and it is not putting out a charge again as shown on the ammeter.

I checked it by bridging D and F and putting the black wire of the DC voltmeter on one of the output holes and the red wire of the voltmeter to earth - my electrics are set up for positive earth.

It is as if it is losing its "field" if that is the correct phrase.

If I flashed it again I am positive it would work again for a while again.

Any suggestions gladly received.

Regards

Pat

email (option): sacombsashtrees@hotmail.com

If there is any residual voltage in my dynamo, am I right in assuming I cannot use my cheap multimeter to measure resistance across the Field and Dynamo windings?

I cannot get a sensible reading from either. If I use a continuity test, it bleeps on both "F" and "D" (probe in "F" other probe to earth or probe in "D" other probe to earth).

email (option): sacombsashtrees@hotmail.com

Try putting it back to negative earth and try again. Sounds like a polarity issue between battery and dynamo. Also check the polarity of the battery I have come across them reversed. Makes it interesting when charging two batteries in parallel!

You can't reverse the polarity from positive to negative earth if you are using an electronic regulator...These must always be used with the polarity of the system set up to that of the regulator...

If you have a standard Lucas regulator you can run it either way when everything is set up to suit...Ian

email (option): ian@wright52.plus.com

residual voltage ?
it would need capacitance to provide this, and i cannot see where that would be? .... if and i mean if, there was any 'residual voltage' earthing each output wire in turn would dump it.

I think you mean residual magnetism - not easily measured using a simple DMM. Flashing produces this residual magnetism in the field (armature) laminations - with the polarity in the correct direction to generate power when the armature turns.

If you are getting inconsistent resistor readings .. then ask the reason why? Inconsistent methodology, dodgy connections, etc.......

A resistance check across the armature and field winding's (plenty of info on this site how to do) should be easy and relatively reliable using even a cheap meter.
I think you need to go back to basics and stop trying to measure at the F and D connectors.

If you really want to change earth polarity for some reason (there needs to be a good reason!) then insulate the electronic regulator from the bike and run the relevant red/black wires to earth/dynamo etc.
Don't do this unless you or someone competent understands what he is doing .. otherwise run whatever earth polarity the electronic regulator is set at.

The bike has been positive earth since I got it and has a solid state voltage regulator set up for positive earth.

My problem is that the dynamo will put out a charge once I have flashed it (using the "negative" lead of the battery to "F" for a few seconds). After a few hours of standing, the dynamo will stop putting out a charge. The 6V battery is fully charged.

My logic was that either the field winding had failed or the dynamo winding had failed i.e. checking the resistance across them one at a time.

As I have no reference points for either, I thought around 3.0 Ohms for the field winding and around 0.6 Ohms for the dynamo winding.

I cannot seem to get any resistance. If I continuity test it both F and D bleep - I do not know if this is normal.

email (option): sacombsashtrees@hotmail.com

ps I thought that how I was checking resistance on the windings was how you did it. Happy to try other suggestions.

email (option): sacombsashtrees@hotmail.com

My B33 had a similar problem worked when you flashed it but no charge after standing. The fault was with the solid state regulator. I have had no problems since changing it.

Hi Ian

Just did a diode test on my solid state regulator and it is faulty.

What did you replace yours with?

The Wassell ones are cheap, but a DVR2 seems to be the one to get. I can convert to 12V with a DVR2.

Regards

Pat

email (option): sacombsashtrees@hotmail.com