65 Valiant oil light only flickers when key turned

Electric "circut" (circut MUST make a "CIRCLE" and that means the "GROUND" has to be GOOD) Had a friend buy a "starter", and a "battery", even change the points,cause he had trouble STARTING his car,,,,I told him to take the groung wire off the block, clean it up, (it was sitting for years) and IT STARTED RIGHT UP !
Good Luck.........