Signal lights and 4 way/ emergency, flashers are fused separately, and each have their own flasher. Check the fuses with a test light or a volt meter, for the turn signals the ignition key will have to be on, 4 way will be on a battery feed . Always test fuses with a volt meter / test light ; looks good , isn't always good. Check the turn signal switch wiring connector at the base of the steering column, sometimes the connector can get pulled loose while using the tilt / telescopic functions on the column. If the fuse check out and you have tested power at the flashers , then at the turn signal switch multiple connector on the base of the steering column, and can't get power back down the column from the signal light switch, that's where your problem is.
99DSDP 3884, Freightliner, XC, CAT 3126B, 300 HP /ALLISON 3060
2000 Caravan toad, Remco & Blue Ox.