A strange electrical failure?

Hello. I wonder if anyone can shed some light on a very odd problem that has occured to my P reg Transit.
My indicator lights have ceased to work...ALL of them!
The relay makes a rapid 'ticking' sound (usually heard if a bulb fails) but NONE of the lamps work. I changed the relay over for an identical Ford one, and still the problem persists. I checked the bulbs at the rear of the van, and they are still useable. The only other strange thing is, when the hazard warning switch is depressed, only the red warning 'tell - tale' inbuilt into the switch lights, and it will NOT go out until the switch is off. Incidentally, when haz lamp switch is 'on', still no lights, (except for switch lamp) I did leave the van parked with hazards working the previous day for a couple of hours, and all was well until this morning.