The car is a '61 210 with a B18B from a 122.

When I first got it about a year and a half ago it was not charging. Replaced the generator with a working unit, all went well (previous owner had also just replaced the voltage regulator trying to diagnose). About 5 months ago, the pulley on the generator came apart in 2 pieces (one of which I never found).

I replaced it with an internally regulated alternator, which failed a month later (zero voltage output). I've gone a few months without addressing the issue, as I only drive the car about 8 miles/day and have just been trickle charging the battery regularly.

Now I have 2 alternators from later 140s (the ones with 2 B+ terminals), though they're in fairly unknown condition. Put the first one in, output was only 5v (12.5v at the battery). Decided to move on to the 2nd one without diagnosing the first and it came up with the same output.

The wiring has always been a little hokey, so I went through and cleaned things up, thinking one of the grounds might be messy. After checking all the connections and cleaning up grounds, no change.

Wiring is essentially this: http://pigeonsnest.co.uk/stuff/volvo/images/volvo-charging.png

I would consider it curious if I have 2 alternators that have failed in very similar fashions. I'm guessing it's more likely that there's a fault somewhere else in the system, but not sure what would cause such specifically low voltage.