right rear signal not working. fast flasher but when changed nothing works atal on 1990 Toyota Pickup

every bulb changed, even swapped complete light from left to right. has no backup lights. can be cause? manual trans. when flasher is changed I get absolutely no lights at all. cleaned all sockets and checked grounds. really need help

Asked by for the 1990 Toyota Pickup
Ground circuit problem. You have gone about as far as a DIYer should go, get a car savvy(er) buddy or mechanic to help.
1 more answer
poss bad bulb socket