Old Bus Issues

[Bus W*nker]

Hi all,

New to the club... (and forums generally), but I have come across a problem and I wonder if anyone can help.
I posted this in audio/video/electrical, but then thought perhaps it is more relevant here...

I have just bought my first ever Toyota, hurrayyy!!!!... and its a bus, ha ha... a Toyota Caetano Optimo.

My hazard lights don't work!

All indicator lights are working, but when I press the hazard switch they do not come on together.
If the indicators are on and you press the hazard switch, it disrupts the circuit and the indicators stop.
If you remove the switch, the indicators stop working too... so everything is obviously wired through the hazard switch.

I have replaced the "hazard switch" and "a flasher relay" (the one that ticks when the indicators are on) and it has made no difference.
There is a second "flasher relay", which doesn't seem to do anything, but I have swapped the flashers around and they all seem to do the same thing... so I don't think its that.

I have changed all of the blade fuses and bulbs etc.., but does anyone know if there is a "bigger" fuse and or relay that I should check? I'm hoping I have just missed something. 

Or... does anyone know where to source a workshop manual or wiring diagram?

Looking forward to hearing from you.

Many thanks,
Steve