if you are sure there is not 12v on the red wire going into the light you must have a bad connection or broken wire.the red wire is fed from fuse F1 20amp. this wire goes to the passenger interior light,does this work?then it goes to the passenger rear reading light,then to the boot light.after boot light it turns brown/white to boot switch.cannot be F1 as you would loose several circuits.check lamp,remove boot switch and clean ,fit with good negative to car frame.check all connections.hope this is of some help.
xs11
March 2010