https://www.curbsideclassic.com/blog/history/automotive-history-wilcot-flashing-indicators-on-a-1933-morris-isis/
The Wilcot solution was adopted by Morris for the 1933 range, except the cheapest car in the range, the Minor. In essence, on either side of the car, was a block of three lights looking very like a traffic light with red, amber and green elements. The idea was that the colour or combination of the colours, showing on one or both sides would guide adjacent traffic of the intentions of the Morris.
Combinations were more complex, inevitably, than just flashing orange lights. Ahead of a need to indicate, the driver would activate the system which would start with both left and right amber lights flashing, like modern hazard warning lights, meaning “Caution”, ahead of an indication being given.
The system was controlled by a knob inside the car, with a spring based plunger acting as a time control for any selection. To indicate turning right, the driver would then request the system to show red on the right and green on the left in a way that almost echoes nautical practice; bearing right was amber on the right and green on the left.
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Morris threw a tantrum after the MoT approved the use of blinkers on rival Ford cars and vowed never to install them.
The MoT ordered the Wicot "traffic robots" removed and so Lucas trafficators were used exclusively in the UK until Morris was sold to Pressed Metal Holdings in the 1950s (in Australia and Canada blinkers were required by law).
The thousands of unusable traffic robots were used in the foundation for a new factory in Cowley. Also used were used brake pads and used sump oil to keep the dust down.