[Healeys] Wiring Problem

[Bob Johnson]

BJ8 Phase 2. Original positive ground. OK, I installed a mechanical brake
switch on the brake pedal. Wired as follows: Tied a wire from this switch into
the green purple wire that goes to the brake lights using a double connector
from and old harness. Then, because I wanted the brake lights to come on
whenever I touched the pedal (like an modern car) and because I do not have a
radio in the car, I wired the other side of the switch to the brown radio
wire. This works perfectly, except... whenever I stop the car and turn off the
ignition switch, the motor continues to run until I take my foot off of the
brake pedal. I don't understand why it works this way. Can anyone explain it
for me? I don't believe that the car would continue to run if I had a radio
on, turned off the ignition, but not the radio. Does anyone know if I can
actually do what I want to do? If so, what is it?

TIA,

Bob Johnson
BJ8