You should probably either refurb your fuse box or get a new or refurbed one.
I drilled the rivets out of mine and soldered the laminations together and
tapped the holes for 6-32 machine screws.
Also you should check all your grounds, starting with the ground strap between
the engine and the frame.
Make sure that your lightbulbs are the right type, same size both sides, etc.
Make sure your light socket contacts are clean. European cars electrics seem
to be made of an alloy that develops an invisible protective insulating film,
so they look OK but do not conduct electricity. Scrape till shiny!
Most of the individual components are fairly trouble-free when they get the right current.
--
George Downs, Bartlesville, Heart of the USA!