96 E320 Neutral Safety Switch Issue
 

TLDR - I believe the neutral safety switch on my car is faulty or loose. I have no clue on how to test this or bypass it, and previous threads I've seen here or elsewhere no longer have the images or clear enough directions for me on how to test this. I need my car ASAP for errands, appointments, and mostly work. I just do not want to spend $250 to diagnose and then another $250 to replace something that winds up not being the issue in the end as it tends to be with this car.

So, I recently was involved in an accident with my daily driver and needed to start using my 1996 Mercedes E320 until I could replace my total loss. The car had in the past given me an issue that during cold weather the car would not start. As of recently, I came to the realization that the neutral safety switch was possibly not working in Park and tried starting it in Neutral. This worked. It happened only a couple times and I thought nothing of it at the time, I go out to the car on a regular basis and start it to make sure the battery stays charged, and everything stays functioning to include taking it on some drives on occasion. It had been at least a year since this took place and have had only random check engine lights which have been resolved by disconnecting the battery to reset the code/light. But low and behold the day after when I really need the car, it starts and after going to an appt the car fails to crank. Everything comes on, no error lights, but the starter doesn't even make a noise. I have to wait, move the shifter from neutral to park, back and forth, trying in each position until I can get the car to start. The car will start and I let it run now just to make sure again that the issue is possibly the NSS. When I turn the car off, the position that started the car doesn't always repeat starting the car. From what I can tell of having it work while in Neutral and not in Park, that it would be the neutral safety switch.

Any help would be appreciated.

Because you did not post your VIN, do you have a 722.3 or a 722.6 transmission?

Vin: WDBJF55F7TJ014830

As well, I went out and got it started (done in neutral) and put it on ramps so I could be able to get under it and take a look when the time comes. I checked the ground wire to the starter solenoid to make sure it's not loose. Even listened it up and moved it around, retightened I check all the fuses in the fusebox on the driver and passenger side boxes, and all are good to go. Tried to start in both park and neutral, got nothing. Tried again in park and got the car to start two times consecutively, would not go for a third. I did notice that when I turn the key I do hear a click, but only once. Not several times like one would hear with a dying battery.

I have checked the 722.3 four speed wiring diagram for your VIN and could not find any so called neutral safety switch, however besides the starting switch there is a starter lock out switch which I have assumed to be what you are talking about. Without the diagnostic equipment I don't know how you would test either switch to duplicate and solve your issue.

Well, I'll have a better idea tomorrow afternoon. I have a mechanic from yourmechanic coming out to diagnose the problem. $70 for an estimated hour of time, but it will move me closer to knowing for sure as I don't have a voltmeter to test anything and it could be a couple days before I could get my hands on one and have the time.

EDIT: I'll update when I know more. Reading around I'm afraid it may be the ignition switch or N65 module.

Neutral Safety Switch
Starter lock out switch? I figured it had one since I have seen this part while I was underneath the car today. -> https://www.eeuroparts.com/Parts/832...EaAvJtEALw_wcB
https://cimg0.ibsrv.net/gimg/www.mbw...229a596997.jpg
It's between a fluid pan and the transmission and it is a punk to even assess because space is so tight.

Mechanic has shown up, bypassed/jumped the starter and got it to work, so that is not the problem

Turns out that it is the shifter linkage bushing is missing on the transmission side. Mechanic was able to find a shifter spot where the car would start continuously, at which point he crawled back under the car and saw the problem.

So it's not the module, the starter or the safety switch.