Anyone clued up on volvo electrics..?

as title suggests.

since getting my daily runner on the road [volvo 460 turbo] ive had an annoying problem with the boost/oil press gauge light not working along with the heater dial and the clock!
i thought it maybe the bulbs,but it isnt as ive fitted new ones and still nothing:scratch:
the rest of buttons,dials etc light up as they should.

ive checked behing the gauge,clock etc for breaks in the wire but there all fine and havent been messed with. ive also changed all fuses too.

does anyone have any idea on what else i should be looking at to sort this out??