From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Wiring diagram blueprint showing connections from a switch box to various vehicle electrical components.
| Identifier | ExFiles\Box 168a\2\ img330 | |
| Date | 9th June 1931 guessed | |
| EL436, SWITCH BOX, WINDTONE HORNS, STARTER RELAY, CIGAR LIGHTERS, TRAFFICATORS, RADIO, BODY LAMPS, STOP LAMP, CAR HEATER MOTOR, PETROL PUMPS, IGNITION, FOG LAMP, SIDE AND TAIL, TO HEADLAMPS | ||