1997 mercedes wont go in drive until i have driven in 3rd gear

Transmission temp sensor could cause this. Depends on temp out side on whether it is bad or not.

sounds like an internal gearbox issue so other than changing the transmission oil there is little else i could advise so it will need to be inspected by a mechanic , sorry no easy fix that i can think of

That's in you gear box. Have a mechanic check it out.

In my experience servicing your transmission is often an excellent way to assessthe actual condition and possibly even discover a solution.

yes it could be, try driving in 3rd gear and see if it still does it.
tcc still works in 3rd.
when was last full tuneup?

Some cars came with this light to help the driver know when to shift to the next gear. IE: 1st, 2nd, 3rd and so on. It will not indicate when to downshift to a lower gear. It's main function was for optimal mileage and proper RPM shifting. Happy driving.

Could be faulty speed contol sensor.

In most cases it is called a "3-2 Shift Solenoid" and it is located inside the tranny. I would take the vehicle to a Mercedes dealership and for about $30.00 they will confirm this by using a computer diagnostic device. I feel that most dealerships have better equipment for detecting this kind of problem.Then after you can decide on a repair garage of your choice to do the job!

Check your digital dashboard to see if your gear is in 3 and tap to the right twice to change it to D.Otherwise you need to visit a mechanic.

could be your kick down cable adjustments