Charging Problem with R90/6

[Hogy]

Hi all, I'm new here. I hope you guys can help me out with an electrical problem I'm having with my R90/6.

The Generator lamp stays on at higher rpms, indicating that my battery is not being charged.
This is a bike I recently rebuilt, battery, diode board and voltage regulator are brand new. If I understand correctly, that only leaves the alternator as a possible suspect. The rotor provides the ground path for the bulb, so it must be good.

When I attach a Voltmeter to the two brushes, I only get about 1.2 to 1.5 Volts, at all rpms.
What should that tell me? Any idea what I could try short of replacing the entire alternator assembly?

Thanks in advance for any tips you might be able to offer.

Hogy

[kbasa]

The airheads have some good discussion here. (http://www.airheads.org/index.php?Technical%20Tips+Charging%20%26%20Batter ies)

[James.A]

When battery voltage drops under 12, or there-abouts, the voltage regulator should direct battery voltage to the rotor to magnetize it and activate the alternator. Try taking your voltage reading at the brushes when the battery is discharged enough to be wanting to charge. That way you'll know if the regulator is working properly. Also, try to isolate the brushes from the rotor and read the continuity of the rotor. Pull the brushes up on the springs and slip a piece of paper between the brushes and the contact rings. Read continuity across the contact rings thru the windings. I run /5's now, but the systems are very similar. The rotor and the diode board are the most common problems I have encountered. If you e-mail me, I can send you a spare /6 field winding to swap out for trial.

[Hogy]

Thanks for the input and generous offer.
I spent all day Sunday taking the whole electrical system apart, alternator an all. Ran every test I could think of, including the ones suggested here. Replaced lots of rotten wires and connectors while I was at it.
I found the problem, it was stupidity on my part. I had switched two connectors when installing the Thunderchild diode board:banghead .

Good news is, I now have a cleaned up electrical system with new wires and connectors, and the bike runs like a champ.

Hogy

[kbasa]

Sweet!