Do they use a separate relay to the indicators

or is it more likely to be the switch

 

I think its the same relay Matt but am not certain mate. I would short out the switch to test it.

 

The switch is crap. I had to dismantle mine to fettle it as it was sticking on. Maybe worth a try but it's pretty fiddly.

 

As said try the switch but mine failed mot on this and after taking dash and switch apart it turned out to be a corroded fuse.
Good luck cheers steve

 

switch first
the relay means getting your hand cut to shit as it's tucked up behind the top of the steering column behind the dash clocks, and even with the clocks out you may not be able to get to it

so hope it's the switch or a fuse, different fuse to the indicators as to the hazards from memory

 

As said the switches always stick/jam, I now exercise mine a few times everyweek.
Take the hazard switch apart, it is a bit fiddly, but clean out all the crap, then put in some beeswax, this is ace stuff for this sort of thing, failing that some silicone gel, I did my dads one on his 83 x4i a few years back still as good as new, only ever used for mot and works fine.
tabetha