I have been having intermittent starting issues with my 240 for several years now. I thought that I had resolved the issue by replacing the starting motor, but as it turned out a broken bolt had created charging issues which led to a misdiagnosis in the starter replacement.

My question is this. Does that mean it is the neutral safety switch, or is a possible question at the original source of juice to the starter at the key turn end of things? Could the third switch position, the one that tells the starter motor to crank, being failing intermittently?

When I turn the key and the issue exists all I get is the electrical turn on with no electricity getting to the starter.

Since it never happens while the car is running I know it has to be in this source to the starter motor chain.

 

What about the od relay? Front passenger left leg panel could be grey or yvory or orange. This was my prob.

I also noticed that coming to a gas station etc....full stop put in park..it would not fully engage in p so i would rock the car a little until i would hear a click form the tranny...then it would start...

Maybe this helps....

 

Couple of things here...if you don't already know, you car is in the age range where the wire insulation under the hood was biodegradable. Your issue could be in any variety of places. Diagnosing electrical gremlins in person is tough enough, doing it on the internet is impossible. All we can do is make suggestions where to look.
1. When it won't start...Key on, engine off...all warning lights on, yes? Do they go out when you turn it to the start position? If yes, probably not in the ignition switch.
2. Even though the starter has been replaced, try rapping on it w/ a wrench while someone has it in the start position. If it goes, it's a bad starter.
3. On the driver's side firewall there should be a red, single wire w/ female connector. Nothing is plugged into it. If you run a 12 gauge wire from it to the starter solenoid (remove the small wire from solenoid and replace it with the jumper) you will bypass your neutral safety switch. The car will now start in gear, so be careful. I have driven my 760 for months with this jumper in place. If your no-start seems to go away, you know here your issue is.
4. I can't stress this enough...with the flooding of our country with inexpensive, low quality parts from China, never discount a part just because it is relatively new. It could still be bad. Bosch buys Chinese product...their rebuilt starters used to be great...not so much now. So...it could very well be the solenoid on your starter has taken a nose dive.