TR3 ignition light

[KGeromini <KGeromini@aol.com>]

Hellow listers,  need help.
Can somone tell me how the ignition light works on a TR3B.  I have had some
times when after driving for a long period of time and the engine is hot, the
light comes on and goes off only after going through the gears, then comes
back on when cruising.   What causes the ignition light to work. where is it
connected and what causes it to go out after the engine has warmed up.  Would
appreciate some help in this.  Thanks.