Signal lights not working!

My friend has a 1985 Cutlass Cruiser and his signal lights don't work. His 4ways work but not the signal lights. We have changed the flasher,bulbs,signal light switch,fuses and the signal lights still will not work. Does anyone know where the problem might be.Another Question is there 2 flashers or just one in the 85 cutlass cruiser

Need flasher or one of lights are dead. Once one dies it won't let you use blinkers anymore. I guess that's their way of telling you one of the lights is out. Nick

Need flasher or one of lights are dead. Once one dies it won't let you use blinkers anymore. I guess that's their way of telling you one of the lights is out. Nick

Might want to check with a test light to see if there is power at the fuse.