DUFF DYNAMO

[Goldie]

I have 2 "Goldies" with mag/dyno's, and strangly for some reason both dynamo's have ceased to chuck out power.
Both bikes have been laid up for a couple of years, and i have cleaned the part that the brushes run on.
I have even tried regenerising the dynamo, by touching the battery live (positive earth) a couple of times on the fields terminal on the end of the dynamo, and yet still no life.
Any ideas?

[L.A.B.]

Maybe some useful info here?: http://members.aol.com/PODtronics/generators.html

Or here, even though it's for car dynamos?: http://freespace.virgin.net/tommy.sandham/dynamo.htm

[Goldie]

Maybe some useful info here?: http://members.aol.com/PODtronics/generators.html

Or here, even though it's for car dynamos?: http://freespace.virgin.net/tommy.sandham/dynamo.htm

Thanks for that LAB.

How i hate electrics. Looks like there will be a lot of daylight ridin' for the future, until i get around to sorting the problem.

Strange how both bike have the same problem at the same time.

[twolitre]

You cannot re-polarise or regenerate the dynamo poles by 'touching' the field terminal with a live wire.  The wire needs to be held in contact for 5-10 seconds.  Also, I presume the outer casing was earthed.
  If you join field and output terminal together with normal wires disconnected and connect a voltmeter between the (joined) dynamo terminals and earth the voltage should rise with engine revs if the dynamo is ok, but don't over do it!  On its own, if the residual magnetism in the field poles and the field windings are ok the output terminal should produce about 2 volts on a 12volt system (presumably less on 6 volts, but I have never meddled much with 6 volt dynamos).  
  If these tests are ok it is probably your regulator.

[Goldie]

Thanks Twolitre.

Maybe i sould try holding the live wire from the battery on to the fields terminal longer as you suggest first.

[Goldie]

Decided to give the 500 Goldie a run today, but before leaving the battery had gone flat, hence no lights,horn, or brakelight, but went for a ride anyway. "Sorry officer they were working when i left home"

As i rode up the road i noticed that the amp meter was showing charge, something it has not done since being in my ownership, and soon all the electrical bits were working as the battery took a charge from the dynamo.

Could it be that because the battery was fully charged before, that the amp meter was staying in the middle, and when i put the lights on it showed a discharge.

Anyway i am not moaning now, because what ever has happened it seemed to have fixed its self.

All i want now is the 350 to do the same.