I have a friend that purchased a 1987 Mercedes 300 E. She is having starting problems. She has had the car in to be checked out but, they cannot find anything wrong.
The 1st time the car wouldn't start, she had a mechanic come he thought he'd have to push it to start it but out of the blue the car started right up. Yesterday when she was leaving work to go home she started the car and got nothing. She said, no noise of the car turning over. The lights would turn on when she applied the switch but then of course go out when she turn switch off.
Please if anyone has any suggestions I would appreciate feed back

Could be the neutral safety switch (NSS), or the bushings on this switch. Lots of info on this item can be found by searching this message board. It the car will not start in 'park' but does in 'nuetral' then you probably need to change the NSS.
regards,
Mark

To check it, just start the car in N to see if it will start. If start with no issue, then you know above stated is the problem.

What is the battery's condition?

Thank you so much. I had my friend put the car in N it started right up. She was so thrilled, as I am. Thank you so much again.

Ok if that was the problem than ok,but if the lights go out whwn you turn the key than it might be the battey alsoor loose conection ,even maybe the ignition switch...

with no luck then, the battery may be going sound. Replace the neutral safety switch. It is not that hard and/or expensive...

__________________
J.H.
'86 300E