My account of dealing with the electrical system on my 1971 E-Type Jaguar, which taught me things about automotive electrical design philosophy that no formal education could have provided.

The Lucas electrical system has a reputation that is both deserved and exaggerated. The components of the era were adequate for their application when new and maintained. The problem is that they were never maintained — British car owners deferred electrical work because it was mysterious, and the deferred work compounded into systemic failure.

The positive-ground system on early cars surprises people who learned on American cars. The convention is different but the logic is identical. Everything works the same way; the polarity of everything is reversed. The conversion to negative-ground is straightforward if you want to run modern accessories but creates documentation complexity for a concours car.