Ogodno, please not that. I just got though troubleshooting a Jaguar. Found and fixed the problem a few minutes before I was considering drinking all the antifreeze and ending it all. All day for a two dollar diode, and I HAD all the manuals.
Now they probably hate me for fixing it. Lucas, Prince Of Darkness. The alternator is a Bosch, though.
I owned 4 of these cars during my mis-spent youth. All were lovely but had the dispicable Lucas electric system, where no manufactured piece was ever rejected for being substandard. A mechanic buddy from Des Moines (more mechanical than me) uncovered a Delco of England cross reference manual. Turns out a Pontiac voltage regulator and (with minor modification) a Cadillac Delcotron alternator worked perfectly. Mallory made a replacement distributor that was a drop in. The starting/charging problems with my Jaguar were resolved.