Also do you know which one is the low tension wire?
All wires can be considered as low tension except the one with
the rubber cap, at the middle of the coil.
If you have Bosch coil look for "15" and "1" mark at the terminals.
Terminal marked with "15" is the positive feed of the primary winding.
This terminal is supplied directly from the ignition switch with +12V.
The "dual spade" on the "15" terminal provides power loop (+12V)
towards the ignition power module.
The other coil terminal, marked with "1" is the negative terminal of
the primary winding. This terminal also has a "dual spade". This terminal
will be pulled towards ground by the ignition power module, when it
receives the trigger signal from the points or the pickup coil in the dizzy
(depends on model).
The rev counter is connected to the other end of the spade on the terminal "1".