I'm not sure this old style hazard switch/blinker relay will work with LED's, unless you keep the existing blinker relay (i believe you recently fitted a new style electronic relay?) and use this hazard switch to switch the other relay. Has anyone done this successfully?
So, having read more on this, seems the early hazard switches, which were supplied as an option, work alongside the original blinker relay, not instead of, so it will switch the old style relay, or a new relay if you've replaced it when fitting LED's