it is the correct bulb. from a local motorfactors and he tried my bulb that i thought had blown.
so i have three off the same double filament bulbs and all have two contacts on the bottom and all have been tested and work fine.
something is wrong with the bulb holder part of the cluster

there is feed getting to the contact that lights the brake filament but no feed going to the contact for the main light filament.
there is a difference betwwen the ukdm bulb holder and the jdm one. a friends lude was a ukdm but before he bought it everything had been fitted to make it look jdm, so when his rear lights started giving him trouble he fitted clusters from a jdm and the 4ws light came on. so i went to him with the clusters from my old ukdm and when we fitted them his 4ws issue was gone and the light went out.
so there must be some difference in the circuit boards in the small boxes to be found in the bulb holders
