Since I've had my Bug, the generator light has been steady on. The
wiring harness is a nightmare and since the battery has been getting
charged....simpler just to not get involved. It's always made me
nervous though, and sure enough I recently had the belt come off due
to an under-tight alternator pulley nut. The engine overheated before
I realized anything was wrong, though thankfully it was just around
town and not on the highway where some serious damage would have been
Realizing the error of my ways, I set out to fix that damn light. The
car (a '74 standard) has had an alternator conversion, but whoever did
it used some creative wiring. At the alternator, there is a large red/
white  AND a mysterious black wire  connected to the B+
terminal, and a mysterious red wire  connected to the D+ terminal.
I tried connecting the hacked-off remains of the green wire to the
alternator, but it did nothing.
Today I started monkeying with it some more and only after finding
Speedy Jim's pages on the subject (highly informative, kudos to Jim)
did things finally make sense. So, I spliced the blue and green
wires from the regulator together and replaced the mysterious red wire
on the D+ terminal with the green wire. Unfortunately, the light
STILL doesn't work as it should.
I am fairly certain it is wired correctly, and the light does come on
with the key, but stays on while the engine is running (however, its
brightness is now directly related to engine speed, whereas before it
was inversely related). I believe the problem is that with ignition
on and engine not running, the voltage at the green wire is a measly
9-10 volts. The D+ terminal puts out 14-15 volts when running. I
figure the wiring on the ignition side of the light is just so shoddy
that there is enough "backflow" though the warning light to keep it
on. The voltage at the red wire (that was previously connected to D+)
is more like 11-12 volts, still not equal to the battery voltage but
closer. Now that I'm thinking about it, I'm not even sure how the
warning light was working before, as the blue wire wasn't connected to
anything before I started...
So, anyway, does anybody think I have a chance at getting this working
without rewiring the entire car? I fully intend to do that, and
soon, but it would be nice to have the light working in the
meanwhile. Also, I figure it probably isn't good for the alternator
to be seeing that low of a voltage at the D+ terminal. Would I be
better off just using the mysterious red wire until I rewire the whole
damn thing and put these issues behind me?
 The red/white wire appears to be correctly spliced into the
battery and fusebox.
 I have no clue where this goes.
 No clue where this goes either, though it does not appear to be
the red wire that used to go to the regulator, as that looks
undisturbed under the rear seat.