I am new to this forum so bear with me.
I have a S320 MB that intermittently wont start. By wont start I mean nothing happens when the ignition key is turned EXCEPT all the dash lights are illuminated. No selenoid click or any indication that it is trying to start. The MB field service tech did the following: locked and unlocked the car with the remote, then did the same with the key at the drivers door and the trunk. Nothing. He then removed the hot battery terminal, waited a few minutes and it started???
A trip to MB dealer suggested the ignition switch was a likely suspect. I declined the repair. A week later, same problem. I removed the Hot battery terminal but this did not fix the problem. Waited about 10 minutes and the vehicle then started.
Back to MB. Paid $400 dollars for the ignition switch. OK for about 4 weeks, then same problem. Same resolution as before. Took off battery teminal, waited for 10 minutes then starts Ok.
Back to MB dealer, Had car for 3 weeks, started it repeated and it never failed. The dealer has assured me the battery is OK, The starter, as best they can tell is functioning properly
They have no clue as to the problem and in fairness if "It aint broke, they cant fix it". ( Did keep my $400 tho)
Any help or clues as to where I could look??? I cant be the only MB owner in the world with this problem. Is there some trouble shooting procedure that would identify this problem?? Thanks

I own a 95 C280.

I have the exact same problem!

Does your engine cranks but can't start?

No does not crank!! Just all the dash lights illuminate and nothing else??

Have the starter solenoid checked out. If you're not getting at least a "click", it isn't functioning. Might not be getting power, but might be bad too.

I sometimes have this problem with my 98 e320. I find it happens on dry days when my key has been in my fleece pocket. If I run my thumb across the end of the key it will start every time. Its almost second nature to me now to wipe the key with my thumb as I unlock my doors.

Not sure if it's related to your issue but hey...worth a shot.

Dont think it is the starter selenoid because of the way it is acting. The dealer has checked all the electrical connections/components and all seem OK.
The static electricity could be a thought. The next time this acts up I will certainly try it.

It's weird because when this occurs, it always starts later.
Thanks for the input.

I am having this problem with my 956 S320. What ever happened with this issue in your car? Thanks for your reply...