Does that mean it uses both contacts in parallel to share the load? maybe that's why I went through a couple of sets already, someone put in a single contact and I've just been replacing like for like rather than what's supposed to be in there.

KIA, More dirt for ya dollar! 99 Sportage, Pod filter, Bosch Super4 plugs, electric thermo fan, racing pedals, Narva 100W driving lights, Yokhama 235/75R15 Super Diggers....getting to the rest bit by bit.