Hello ballarddog,
I`ve made a similar experience some weeks befor leaving for the Event of the Year in Scotland. SUDDENLY one of my
12 fuses (Car was converted in the Netherlands for Rallying some years ago) blew during starting the engine, but only when pressing the brake pedal. I checked the electrics several times, found nothing wrong until a friend (car mechanic) discovered that a faulty brake switch was the problem. After changing the switch I had no more problems, 2500 trouble-free miles this summer

.
Good Luck
Dietrich