Author Topic: Neutral Safety / Inhibit Switch Part Number  (Read 1602 times)

ScouseJames

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Neutral Safety / Inhibit Switch Part Number
« on: September 07, 2022, 18:19:33 »
The Neutral Safety / Inhibit Switch on my 1966 230SL (US spec) has decided not to function correctly.

I know a replacement will be hard to find but I would like confirmation of the correct part number.

I have found a switch on eBay with the number 0025450524 but from the workshop manual for the 230 SL (as advised by my mechanic) the number is 0015458724.

Can anyone please advise if there was a number change at some point or which is the correct part number?

And please do let me know if you have a spare sat on the shelf in your garage, which you'd like to sell!!

Thanks,

Jim.

Todd

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Re: Neutral Safety / Inhibit Switch Part Number
« Reply #1 on: September 07, 2022, 19:13:54 »
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« Last Edit: September 18, 2022, 23:11:16 by Todd »
Todd

dirkbalter

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Re: Neutral Safety / Inhibit Switch Part Number
« Reply #2 on: September 07, 2022, 21:23:58 »
Prior to dropping $685, I'd drill the flared edge off those rivets, pop that bakelite cover off of the metal backing, and see if I couldn't freshen up the contacts inside.  The backing could then be re-installed using long 2mm or 3mm screws and nyloc nuts.

Did you take pictures by any chance?
Dirk
66 230 SL
70 280 SEL
53 CHEVY 3100
18 C300 COUPE
05 HD FLSTNI

Todd

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Re: Neutral Safety / Inhibit Switch Part Number
« Reply #3 on: September 07, 2022, 22:47:09 »
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« Last Edit: September 18, 2022, 23:12:12 by Todd »
Todd

ScouseJames

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Re: Neutral Safety / Inhibit Switch Part Number
« Reply #4 on: September 08, 2022, 08:21:27 »
Prior to dropping $685, I'd drill the flared edge off those rivets, pop that bakelite cover off of the metal backing, and see if I couldn't freshen up the contacts inside.  The backing could then be re-installed using long 2mm or 3mm screws and nyloc nuts.

Thanks for you advice.  Currently the car may be started in gear (found by my mechanic when investigating the reversing light not working), but it's not something I would do i.e. start in gear, so I may leave this job for over the winter.

But, out of interest, would you say that the $685 part is the correct one?

Todd

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Re: Neutral Safety / Inhibit Switch Part Number
« Reply #5 on: September 08, 2022, 11:24:17 »
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« Last Edit: September 18, 2022, 23:12:53 by Todd »
Todd

lpeterssen

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Re: Neutral Safety / Inhibit Switch Part Number
« Reply #6 on: September 08, 2022, 11:31:49 »
Dear James

I agree with Todd that there is a great chance to service that component and give new life to it.

The other temporary solution is to produce a male Bakelite 4 prong connector with only two pins on it to bridge the signal from the starter selenoid.  In that way T50 signal will pass from one terminal to the other on the Bakelite plug.

You will not have reverse lights but will be able to start your car on any gear, parking, neutral whatever.

Best regards
L.Peterssen

ScouseJames

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Re: Neutral Safety / Inhibit Switch Part Number
« Reply #7 on: September 08, 2022, 15:30:07 »
Dear James

I agree with Todd that there is a great chance to service that component and give new life to it.

The other temporary solution is to produce a male Bakelite 4 prong connector with only two pins on it to bridge the signal from the starter selenoid.  In that way T50 signal will pass from one terminal to the other on the Bakelite plug.

You will not have reverse lights but will be able to start your car on any gear, parking, neutral whatever.

Best regards
L.Peterssen

Thanks for your reply.  I'm lucky that the car starts, it's just that it will start in gear (which it shouldn't but that's not something I do anyway), but the main issue is no reversing light. 

ScouseJames

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Re: Neutral Safety / Inhibit Switch Part Number
« Reply #8 on: September 08, 2022, 15:31:38 »
I don't own an SL and my Coupe is a 4 speed manual transmission, so I don't know if that's the correct part or not.  Maybe your mechanic can take a couple cell phone photos, and those can be used to compare your existing switch, to the one being sold on ebay.  You could also contact your local MBZ dealer, provide them with your VIN, year/make/model, and they could look up the correct part number, tell you if it's still available, and quote a price.

I think this switch would be no problem at all to pop apart, and get it working again.  Prior to that, I would do a quick ohm test on it, both with the linkage hooked up, and then disconnected linkage...because I would want to confirm that the switch internals were the problem, and not the linkage adjustment, or the wiring going to the switch.  For example, have the wire rubbed through somewhere in the wiring harness, so that it doesn't matter what the switch is doing, because the one wire that the switch interrupts (preventing the key "signal" from getting to the starter solenoid) is always bridged and connected between the ignition switch and the solenoid.

The Niemoeller website also lists it as:  001 545 87 24   It's item 36 in the diagram.  https://www.niemoeller.de/en/w113/w113/B042/277/d27221-eletrical-switch

Thanks again, I did find that correct number earlier today.  I will have a look at it again over the winter.