Thought I'd try to help by copying your first post across.
Originally Posted by coloS420
1995 S420 won't crank HELP?!?
My 1995 S420 --- only 60k miles---won't turn over. Lots of lights on the dash. A jump doesn't help. No warning (i.e. NOT hard to start, NO solenoid clicks, NO starter whiring, did not leave lights on ever). Just did not start after stopping at the sis-in-laws.
Tried in park and nuetral (car WAS in nuetral..it started to roll)
got out, locked with 'flat' key and unlocked with flat key still no start.
disconnected battery to 'reset?' things. no luck
I am thinking 3 things:
neutral safety switch
I bought from an estate and never got a 'wireless' key. I am thinking of spending the $200 to get a wireless key (would be cool) to see of this might be a security lockout issue.
Can you help with better ideas?
I don't understand why you would suddenly have a security lock-out problem that a new remote key would solve when your existing key has presumably been working OK.
In my experience, the ignition switch usually gives a progressive indication that it's going bad - i.e. you start having to turn it several times before the starter energises. Don't know about the neutral safety switch but would be surprised if it underwent sudden death. You could try (carefully!) jumping the solenoid contactor to see if the starter will turn.