iirc [and it is only recollection!] 1 is for adjusting the pitch of the headlights [there should be a button in the centre of the dash which flips them up WITHOUT the lights on, to help you change the bulbs] and 1 is for a heated back screen when you have a hard top. FUCK knows what the third is MEANT for as I've only ever seen it used for an immobiliser/alarm light.

HTH