U = Blue. The convention is Blue/Yellow - Spotlamp switch to lamp.

The Red/Orange convention is sidelamp switch to right hand sidelamp, so that's a bit odd.

Consult an auto electrician if in any doubt.

See this link: http://www.mgb-stuff.org.uk/colourcodes.htm


DaveW
'05 Red Roadster S1
'16 Yellow (Not the only) Narrow AR GDI Plus 4