Blinkers and emergency flashers don't work

Start with inspecting the fuses, check fuse #4 and #15. The multi-function switch is the controller for both the turn signals and the flashers, along with a directional flasher unit. These fuses supply voltage to the switch. If a fuse is bad (popped) then it is possible there could be a wiring issue or shorted bulb. If the fuses are good then the fault is likely a component failure and will require circuit testing.