I cut out a couple sockets from an xj in the salvage yard to replace the rusted ones that came with my mj that wouldn't turn on. after splicing them on the problem was fixed. If you have a bad ground, it's not hard to locate. Go to harbor freight and get a cheap multimeter, cut the wires from the socket, trace the wires to where the harness ends at a connector, run a continuity check to distinguish which wires are which, and then test the voltage, and ohms to a good ground compare results to a turn signal that is functioning correctly. I'm a helicopter electrician, most of my job consist of doing the same thing, except with bigger wire bundles lol