oil light flashing on my gpz750 kawasaki?

i have now changed the oil and filter but oil light still flashing still no knocks smoke or noise from engine the light that is flashing is the center one on the L,E,D marked oil on the tank also the ignition light flashes in tandem with the L.E.D display iam thinking oil pressure switch or a wiring fault thanks to the two people who sent me a answer log book says the bike is a 1986 ZX750-A3

simon
February 2010