Rear turn signals

Hello
Confirm that both rear taillights are connected to a good body ground. Confirm that the battery negative is connected to the engine block And to the body. Confirm that there is a good ground to the metal housing of the dash cluster. Confirm that the rear bulb sockets / contacts are in good shape And the lead contacts on the bottoms of the lamps are good. Confirm that the back and sides (ground) of the lamps are clean . Check that the lamps are orientated correctly in the sockets. Last check that you have the correct lamps (1157).
Hope this helps