Chris Green wrote:

[snip boring description of problem]

I outlined the problem to someone else as well and, as very often
happens, I think that has led me to the answer:-

G G - these terminals are the alternator field coil which the
regulator drives to vary the alternator's output. The alternator
has a separate B+ output which actually charges the battery.

C - This is the switched +12v feed from the battery, it provides
power for the regulator electronics and also tells it the battery
voltage.

L - This is L for L[amp]. It would normally have a lamp between
it and the C terminal. When ignition is turned on there is 12v on
the C terminal and 0v on the L terminal so the lamp lights. When
the engine runs L goes up to 12v and the lamp goes out. On my
Hatz there is an 82 ohm resistor instead of the lamp (between L
and C) and L is also connected to the hours meter. The hours
meter is thus only running when 'the lamp is out', i.e. when the
engine is running and the alternator producing output.

W - I still don't know what this is.


I don't know why 'G' means field, translating to German doesn't help.
L for Lamp makes some sense, C for battery +ve doesn't.

--
Chris Green
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