Brake Failure light question

[Terry Rust <trust@domain.elided>]

With this fine explanation:
>The light is triggered by the plunger switch in the switch block/brake
>distribution manifold next to the master cylinder. When a line pressure
>imbalance occurs(such as losing fluid from front or rear brakes but not
>both)the plunger is forced off to one side, actuating the switch. The light
>comes on to tell you that you now have 1 brake circuit bye-bye for some
>reason.
I wonder how you turn the darn thing off once you reseal up the brakes,
fill and bleed, etc. The one has been on in Speedy (70 model 800) since the
engine was out last spring and the brake lines were all replaced. It's been
refilled, bled etc, the brakes work as well as they can but the light stays
on. Suggestions?