If you’re using the B4 book things will be different from a B2. If your regulator isn’t working correctly you won’t charge correctly and could blow bulbs (as the neutral light is probably the only one on then that would go first).
Your manual says there should be a different reading across the coils from what you’re getting, but as long as it’s similar on all pairs of them and not open circuit and not going to earth anywhere I would take that to be near enough. Your meter won’t be that accurate and the slightest resistance across the connections will change the reading (if you haven’t hit the plug connectors nicely or have some crap on them it will change.)
The exciter (field) coil may be causing a fault, check it with your meter again across the two wires. It would be worth checking you get a voltage from the regulator going into the field coil supply wires too.
