All exterior lights flickering

[Moonlite Fingers]

The lights start to flicker about 5 seconds after start up I.e when alternator kicks in. I am getting 14.5 to 15 volts fluctuation at the lamp fittings which I think is causing the flickering. I tested and know the flowing:

1) alternator output seems good, 14.5 volts
2) voltage across battery seems ok with 14.5 volts when running
3) battery good showing 12.6 volts before start up
4) checked earthing straps behind battery (x2) and fitted additional earth strap from block to chassis (using earth point under right hind side of rad, which I have cleaned)
5) also checked two large fuses and all fuses in fuse box

It might be unrelated but she's running rough, mis-firing, most noticeably when running at constant revs ( 2000 - 3000).

I am totally foxed now and don't know what to try next, any ideas?

Moonlite

[Moonlite Fingers]

If anyone's interested, it turned out to be the regulator.

Ran the engine with the output cable off the alternator (which is where the regulator is, situated inside the plastic housing). That seemed to reset it because once it was reconnected and the engine restarted, the voltage at the lights was perfectly stable at 13.98 v and the lights shone consistently (and she runs much better too).

Happy days

[JRH63]

Thanks for the feedback