every ford that i own did the same thing and i just wired up some heavy duty push N pull switches for the headlights and running lights and have never had any problems since !
COLE HERSEE #
50088 Headlamp Switch
Extra Heavy-duty: SPST
Off - On, normally Off. 30A at
12V DC, 6-36V DC. Energizes
two circuits simultaneously
from a common feed for headlamps
and taillamps. Brass mounting
stem, 7/16" -28 thread. 5/16" (7.9mm) long.
Black plastic ****, 10-32 thread with set screw.
Zinc housing. Silver contacts. Sealed with a gasket under
the terminal insulator. Mounting hardware included.