Hi, just got a 1987 300D a few days ago. Ran well until my driveway but the day after the battery was dead and (after having changed it), no way to have it start.
After a few investigations: power arrives to the ignition switch when I turn the key and the starter works (12V on the main wire and when I connect it to the smaller wire, the starter cranks).

So there is something wrong between the ignition switch and the starter!

Question:
1. Any idea?
2. Does anybody have the correct wiring diagram?

Thanks!