Took the dyno out from the magdyno and inspected the commutator. It was clean but I cleaned it again with some wd40 and a towel. The brushes are ok. One was a bit of a tight fit, so I took off a bit of material with some emery paper, now it is a perfect sit. I really could not find anything wrong there. The shaft seems to run straight, I can see that the bearings are new. I still get this crazy volt reading on DC. The tester is a digital type. On the battery’s terminal I still get less then 6 volts. Not to mention that all this is happening with lights off. Because the crazy reading on the dynamo itself, I reject a problem on the regulator. So, What now? Maybe new springs for those brushes?
Those results are exactly what you get when the dynamo is fighting the battery rather than recharging it.
Digital meters are a PIA to use on dynamos, they respond way too quick even with the damping turned on
I wonder if the brushes have been connected correctly i.e. "F" and "D" just inside the dynamo.
They should have been, as the dynamo would have been bench tested when it left the re-winders.
Maybe it is start again.
Reflash to the correct polarity of your electronic voltage regulator, then test the output of the dynamo on the bike, but not connected to the regulator.
Usually electronic regulators needs the battery as a load,
(Or at least a capacitor, Sold dearly as "Battery eliminator"...)
In order to cover for battery absence.
Otherwise the regulator would not work correctly and may be burnt. FYI...
one of the downsides of modern electronics is digital meters without any damping.
I have tossed most of mine & gone back to an analog one when working on the bike.
I bought a very expensive one only to find that I have to preset the range to 00.00 V every time tried to take a reading otherwise it read each contact running over the comutator so it went 0 to 9 V and back a squilion times a second then as the voltage was getting low when the brushes cross the seperator it would automatically switch to mV and became unreadable.
The 50 year old analog meter read a flucuating 6.9 to 7.2 volts.
