[Zeke]

Troubles with Lucas usually started when the battery was going south. Then the poor uninformed owner would take it to Sears and install something like a DieHard that wasn't quite factory spec. The cars of the Lucas era had voltage regulators built by the neanderthals and they went nuts not being matched properly to charging rates. So you got spikes and lows and electrical problems ensued.

Nowhere will you find documented info on this so don't try and take it with a grain of salt. I took the advice of an old Brit who ran an auto electrical service in Beverly Hills 45 years ago and had trouble free British cars Lucas equipped.