usually on pandas with switches and heater control illumination it has a yellow wire that also comes down to light up the bulb in the lighter socket.
you can run a wire down from the switch to make it work as it should or you can wire it into an ignition live. if you have an after market radio, sometimes an ignition live is fitted for the radio. you can tap into that.
you can also run the illumination wire to pin number 6 on the radios ISO power connector to get the dimmer to work on the radio when you turn the lights on.. thats if the radio supports it. most after market ones do.