Can anyone tell me what lights are supposed to work on a 97 a4 1.8t, because I think my car may have been messed with before I bought it.

I have the type with 6? lights inside the speedo and tach, and four big ones in the center, except when I turn on the car, the bulbs may be burned out because the center only shows an oil pressure, gas and another but the bottom right never is on. The ones on the right in the speedo seem to have one that never turns on, but i'm not sure there is one, but the ones in the tach on the right never turn on, and I saw one night they were slightly lit up and it was the check engine, the turn signal warning, the asr and a couple others, but when I pulled the instrument pack out the cable on the left had it's yellow and yellow/black wire not in the connector but attached to a loose light bulb, and there were no light bulbs behind the left side set.

What should this unit look like? Is it right to have a light bulb free back there that's on when the car is?

Any help would be appreciated.