That's where I was at. Full fielded by jumping the F terminal to black (earth), then engine running at 1800 RPM I had no voltage at the A terminal. Notice they are connecting the terminals on the Yoke, and testing the A voltage output on the Yoke, not the wires. This is when I determined the brushes needed replacing. They seemed OK, weren't quite at the wear line, nevertheless I got some brushes from Singapore and voila! Plenty of voltage at the A terminal when full fielded.

I've gotten the slow boat brushes from Singapore a few times. Takes about 3-4 weeks.


Last time I searched, I found relatively inexpensive alternatives in the UK like these.

Thanks for the help so far, going to connect my dark green to black, make sure my meter is on DC (pretty sure it wasn't before!) and see what's what.

Meter on DC, and no voltage. Looks like I'll buy some brushes and try again.

You can get a pretty good idea of how worn they are by comparing to the Singapore eBay photo. The line in the brush about mid-way is a "wear limit point," and just about every AT1 that I've had to dig into the Yoke for charging problems, the brushes are stuck/sticking in their guides and the brush is at the wear limit or past it. You'll need to clean the mica on the rotor, and there are plenty of posts on You Tube and this site for that process, it's not hard.

Did all the dynamo tests in the manual last night, and I'm getting continuity between positive and negative brushes. I ordered those UK brushes, so once they come in I'll replace them and fix the insulation between the brushes, then I think I'll have voltage. Once I get it down there I can check the regulator and battery, I think it might be suspect as well.

Update for anyone else having this issue in the future: a screw holding a brush lead was too long and grounding out by bottoming in its hole. Super simple, now there's voltage!