Fog light problems


sorry if this is the wrong forum but you all seem pretty glued up on electrics so i figured id ask.

car is a - mitsubishi colt cz1 2006 1124cc 5 door hatch back

rear fog light not working i press switch and it appears on the dash that its on but doesent light up on the rear of the car.

ive inspected the bulbs and replaced them also replaced the fuse even though it wasent blown and still it wont work

the bulb is a duel filament the weakest filament being the tail light and the strongest is supposed to be the fog light

the tail lights both opperate correctly but fog wont turn on ive checked the bulb housing and theres 2 pins + 1 ground on the duel filament bulb

im going to buy a multi meter 2morrow to test the voltage but where should i be checking?

is it black to car ground point red to pin and i should get around 12 volts?

do both pins require 12 volts? and theres only 1 ground to ground the bulb?

i obviously have power on the one pin for the tail lights to turn on is that correct?

what about the switch should there be a 12v supply coming from there?

if i cant get 12v on the 2nd filament pin and ive got 12volts from the switch would this indacate theres a split in the loom ( i think its called that) if sop what would be the best way to go to find this ?

sorry if this is the wrong place but no one seems to have a clue on the mitsubishi forums

thanks for all the replys