Neutral Safety Switch

[garwoo]

Help! My Neutral Safety Switch wont let me start my 1967 230SL Automatic. This is the second time. The 1st time the NSS cable to the transmission was loose. Adjusting the cable fixed it. This time the cable is fine but it still wont start. I have adjusted the NSS with the key on and tranny in reverse and moved the switch until the backup lights come on. Unfortunately the lights stayed on, no matter where I put the gear shift.
Any help would be greatly appreciated.
Thanks
Ed

[ja17]

The switch is mounted on the firewall as you probably know. Check to see if it is moving when the shifter is moved. If not manually move it to "start" position. CAUTION take care until the fix is made, since engine may start in drive.  I am guessing that the cable may have bent or become disconnected.

[garwoo]

Thanks for the advise Joe, the shifter does not move the NSS. I will check to see if its connected. Moving the NSS to START did not make the engine turn over or start.

[Jonny B]

One other item to check is the length of the adjustment fitting that fits onto the lever on the neutral safety shift. After having some (!) transmission work done on my 250 SL I discovered that the fitting (with the socket for the ball on the neutral switch) was too short and could not be adjusted any further. I am traveling right now, and not able to measure the length, but I am guessing it should be about 3+ cm.

[garwoo]

Thanks for the advice Jonny,
I will check it out and let you know.
Ed

[garwoo]

Hi Joe,
I checked NSS cable and could not find any kinks or anything else It appears to be connected and moves easily up and down.
Could it be the Neutral Safety Switch is just bad? Is there a way to bypass it until I can find another NSS, (which I understand,are not being manufactured anymore)
I have read all the info in the Tech. Manual but I still can't figure it out.
Ed

[Shvegel]

If you look here the NSS is position 48.  In order for the starter to function you would need to connect the two terminal 50s in the plug.

https://www.sl113.org/wiki/uploads/Electrical/280slwiringdiagram.pdf

Hopefully these numbers are cast into the plastic (Bakelite) of the switch as they most likely would not be listed on the plug.

[Jonny B]

Here is a photo of the ball joint connector to the neutral safety switch on my 250 SL

[Pawel66]

Ed, you are Full mamber now. I will PM you with the NSS connections. If your switch moves with gear selector but it does not free up the starter, indeed you need to check the connections. If you connect both 50 wires and starter still will not start, the circuit is broken somewhere else.

PM sent.

[ja17]

Did you check the starter?

[garwoo]

Hi Pawell66,
thank-you for your assistance and the info, based on that and all the other responses, I can see I'm in over my head and will need someone more experienced than myself.
Its funny that it gave me this trouble, all I did was back it out of the garage for an hour!
It does have a new modern starter, by the way, so we can cross that off the list. My money is on the NSS.
Thanks again Ed
Will report back on the fix.

[Pawel66]

So I understand if you connect 1 and 4 from my message with a piece of wire - then the starter works. This would indicate NSS. Very simple test.

If the starter does not work when you short connect 1 and 4 - it probably is not NSS, it is something else.

If you have voltage as you turn the ignition key to starter position (not ignition, starter position) on wire 4 (and when you connect 1 to 4 it does not work) - then it is likely to be the starter.

Starter NEW, you say: meaning Never Ever Worked.

if you do not have the voltage as you turn the ignition key to starter position on wire 4 - trouble may be in ignition switch.

[garwoo]

Further news on the NSS. My mechanic has been working on getting the car started, it appears the culprit is the ignition switch, plus the cable from the NSS to transmission is
broken. I checked the cable before and it seemed ok, it appears the break was in an out of  site place. New ignition Switches are $237+. Does anyone know if the NSS can be purchased by  it
self?
Thanks once again for all your help
Ed

[Jonny B]

Quick check shows that Buds Benz has them listed on their website
230 SL - $322
250/280 SL - $262

[garwoo]

Thanks for your answer Jonny, sorry I misled you. What i meant to ask was  about the NSS Cable, if it is available by itself?

[Pawel66]

It is in MB, A1132600051, about $70 net in my area. But check which parts you really need. Maybe you just have the end lock broken - then this is a separate part. This cable from MB comes without protective tubing and end lock. End lock is not available in MB. The drawing and parts you have also here:

https://www.sls-hh-shop.de/main/en/mercedes-230-280sl-w113-/27-automatic-gearbox/27-b-automatic-linkage-and-connecting-parts

But check also the US suppliers, which may be more convenient for you. You have the list on the forum (Bud's Benz, Authentic Classic, etc.).

[garwoo]

Thanks Jonny B & Pawel66 For your prompt Response's
Will check with Buds Benzes.
Your assistance and advise were priceless, I could not have got to this point without you.
Thanks also to those who made Suggestions and comments. I have learned a lot.
Ed

[Jonny B]

Quick check of Buds shows their listing at $99 for the cable. Be sure to keep the connector end at the NSS (with the ball socket) those are not the same as the sockets used on the throttle linkage, and are difficult to find.

[garwoo]

Thanks Jonny,
I'll keep that in mind