The flasher unit is the same for the indicators and hazards. I'm guessing the fault is most likely in the hazard light switch..
According to the haynes manual, the flasher unit is either in or behind the passenger compartment fusebox.
Green/white wires go to RH lights
Green/red go to LH lights
Light green/Brown goes from flasher unit through fuse C8 to the direction switch, then on to the appropriate GW or GR wires.
Light green/brown also goes to the hazard switch which I think is what should light the bulbs in the indicators.
There's also a purple/brown wire that goes from the flasher to the hazard switch. I think this makes the light in the switch flash.
The GW and GR lights go from the hazard switch to the lights.
There's a white wire that goes from the ignition switch through fuse B3 to the hazard switch but I can't figure out what that's for.
I think I'm going to check all the connections and if they're ok, try replacing the switch and see if that fixes it.