How about the emergency flasher does it work??? If so and all the lights work it is the flasher remove and replace or try swapping the flasher relay in the fuse panel. I have an 89 so I have no idea what you fuse panel works but it should be the same principle since nothing happens at all. Both the flasher relay for turn signals and the emergency flashers should be next to each other. Check it out see what you find.
89 2.5 TBI, 4" RC lift, 1" Booms, SYE, Adams Driveshafts front and rear, Ford 8.8 with 4:88s, BFG 33X12.50X15, and a ton of other stuff.
AF Jeep Club Tail Number 184