On vehicles with the manual air conditioning controls there is one small bulb that illuminates all three dials
. The bulb is located behind the centre control knob.The bulb no. is a 286 and its 12v 1.2w,
£1.99 from halfords or 45p with a trade card
Turn the knob to the upright position and pull it to remove the centre knob, cover the pliers with some cloth to protect the switch
Bulb Location arrowed
Remove the bulb using either a pair of needle nose pliers with something like a rubber band round the ends to provide grip on the bulb or a thin piece of tubing pushed over the bulb.
Put in a new bulb