92 mercedes 300d radio wiring

[diesellover 92]

So I plan on swapping to a modern single din head unit on the new to me mercedes. The current radio is slow to turn on and occasionally turns off, i also notice my antenna stays down. Is there a seperate antenna switch somewhere. With the quaility of the reception I'm guessing a connection is broken somewhere. Also is there a specific wiring harness for this car or will i need to cut into the factory harness? If so, i'm looking for the pinouts.