gs tacho

[stratocaster-62]

With regard to the G S tacho-the 3 contact type, can anyone identify the 3 contacts.
Looking at the tacho from the back at 12oc there is the bulb holder, at 2oc there is a contact which I believe is the earth as this is fitted directly to the case and at 8oc and 10oc there are 2 terminals one I assume for the live feed and the other for the signal.
My problem being which one is which?
If anyone can throw any light on this I would be indebted.

[tangara]

Looking the back side, left and flat connector with white plastic around is positive.
Central bolted round connector with plastic around is signal and right is eart with a smaller bolted round connector.
I have 2 tachos on the table and both same connecting ...........
Thierry

[david]

if it helps I have the "hints and tips" paper on changing the GS tacho to run on 2 cylinders...email please... and will send.
ds.malbernatAT wanadoo.fr to avoid robot sperm