What's this control

[TeeCee]

Hello everyone, I am new to the Spider world and to this forum. I hope you good or bad folks can lead me through this experience.
I just bought an 82 2000.
I really love it, so far. I've been out just kinda getting to know the car. Poor baby needs some good ole TLC.
My question is;
On the dashboard, right side of instrument cluster in top center panel, where the brake, ex. Gas sensor and seatbelt lights is a knob on the right.
If I were guessing I would say it's for the courteously lights. I'd sure like some help there.
Also, what do I need to know about instrument lights? Bulb locations, what circuit do they share. I bought a schematic drawing but dont see anything about cluster lights.
Thanks for the help in advance.

[davidbruce]

That would be the rheostat for the instrument lights. If you sign up for mirafiori. com their library has a plethora of information. Owners manuals (that identify the controls, list which circuits are on which fuses etc.) Wiring diagrams, trouble shooting guides etc.