No-one has yet discovered an original wiring diagram specifically for the FWD Alvis. However, remnants of original electrical systems on surviving cars show that it was a Lucas system, similar to that fitted to contemporary rear wheel drive Alvis cars, in particular the sporting versions of the 12/50, as seen at this link:
12/50 wiring diagram
The original sports 12/50 system is a bit too simple for modern driving conditions, in that it does not provide for a horn, nor brake lights, nor for twin rear lamps. However, we know that the long-chassis FWD cars did have some of these features. A wiring diagram for the 1928 TA14.75 Alvis is available, which can be used as a guide to what should be fitted on the FWD:
TA14.75 (six cylinder) wiring diagram
From the above two diagrams, a suitable circuit for the FWD, for modern traffic conditions, has been drawn up, as found at this link:
FWD wiring diagram
This makes use of some information from the Parts Specifications, which identify certain items of electrical equipment. If anyone considers that this diagram is in error or can be improved, please contact the website manager at the link on the home page.