The lights behind the dash dials, the radio etc no longer light up. Basically any lights which are dimmable using the dimmer.

ive tried replacing other bulbs which were out, looked at all the fuses i can, but does anyone have any ideas?

is there a specific fuse for those lights? could it be faulty dimmer? faulty LCM?

What year car. ?

If first generation car, could be headlight switch itself.

What happens when you open the door with the side lights only left on?
Does it ding once or keep chiming ?

March 2006 car, 4.2 supercharged

If I leave sidelights on and open door it chimes ONCE .

I’d say you need a replacement headlight switch.

Or open yours up, and rip out dimmer module and bypass to set dash lights to max

you hero, works a charm. if in doubt, get the soldering iron out.

new switch on order then.