Looking in my Haynes manual it looks like there is just one bulb behind the three heater dials that illumates them all. Is this right? as the fan speed one on mine isn't illumated at all, the temp dial is patchy and the direction one is ok.
Before I take it to bits, I've looked everywhere for what bulb is behind there. Looking at the list above is it the:
interior,boot,glovebox 233, or
dash 286t
Cheers.