A brief 23 page booklet on how to maintain the 4 and 6v charging/lighting set on your 1930 motorcycle. The E3 and E25 charging units were not high output units compared to modern charging units but were a major step ahead from the gas acetylene units that were still in use on a lot of older machines. Regulation of the charging system for the battery was a combination of the 3 brush generator and the charge resistors in the headlight, as well as the generator cutout hidden under the end cover of the generator.
Click on the front cover below to see the complete manual.
It is a 4.1M PDF and you will need Adobe Acrobat Reader to view it.
Wiring diagram including detailed description of the operation of the charging regulation resistors on the lighting switch.
For 1931 Lucas were pushing the message that they had motorcycle riders nightime safety at heart.