New NSS still no start w126
 

I put in a new NSS. I still cannot start it without jumping terminals 1 and 3
i doubled checked the wires and its plugged in fine... There is a small wire grounded to the frame that looks like it was redone by someone else. where should i start checking?

Didn't you have the problem with the corroded wire near the junction box?

Don't know if you did this or not; on My Year and Model there is a hole in the Body of the switch and the Transmission Housing that you need to stick a Drill Bit into to line up the switch.

haha yep I think this saga may never end.... its one thing after another.

that is that small black lever and you put the bit into the small hole behind it right? i put those in the slots and then tightened down the nuts...

Call me
 

We need to discuss your diagnostic strategy..



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Did you try jumping the NSS before replacing it and did the engine start with the switch jumped?

Just stating the obvious, and I'm sure you did but, did you make sure the car was in Park or Neutral when you tried to start it?

In the pics below the location inside of the Car for the Electrical Connector that connects the Neutral Saftey Switch and the Back Up Lights.

Disconnect the Connectors. I am not sure on the Wire Color Coding on a W126; but, on the W123 if you jump the 2 Purple Wires (make sure the Car is in Park and the Parking Brake on) of the Connector that goes towards the Engine you should be able to crank the Starter (this bypasses the Neutral Safety Switch.)
That will tell you if the Circuit is good from the Ignition to the Starter.

If you jumper the other 2 similar Colored Wires on the Connector going towards the Engine and your Key is on I am guessing your Brake Lights will go on.
Once you have determined what color the Neutral Safety Switch Wires are turn your Multimeter to the OHM Setting say on 200 Ohms.

The Arrow points to where the Connector is located and in the other pic the Circled one is the connector.

Pick up the Connector that has Wires going down towards the Transmission Tunnel and put pic the same colored wires (Purple) and stick one probe in one side and one probe in the other.
If it is in Park and you stick the Probes in properly you should get some changes in Numbers on your Meter. It could go down to a Point something number or even zero. But, if it moves that means your Neutral Safety Switch is on.

If you do the above and your Meter reading just sits where it is just as if it is not connected you still have some issue with the Neutral Safety Switch or your Shifter Bushings are shot.