cant find live or negative wires

Don't tell me you cut off the factory harness!!! Anyhow, I seriously recomment that you take it to a pro to do the install since some models came with factory amps that you really dont want to screw with.

But I will help you still, Goto this website :

http://www.beckerautosound.com/

Select the "What's New" menu then scroll down until you see

"All Mercedes Benz radios from 1994 to 1997 have the DIN-ISO connector. Click here for the pin out and diagram."

Click on that link and it will show you the factory harness.