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Discussion Starter #1
Greetings,

I'm re-wiring a W126 OM603 wiring harness and had to make repairs on the X26 terminal block, a 12 pin male/female connector directly behind the fuse box.
As some of you probably know, when these connectors are opened for testing or repairs, the pin connectors will pop out despite reasonable efforts to prevent this from happening. In addition, a previous mechanic had made electrical repairs and bungled color coded wires under the fuses in attempts to fix a meltdown on the A/C circuit so I cannot rely on the existing connections anyways.

To the best of my knowledge, the MB repair CD does not provide diagrams for the various the multi-pin connectors used throughout the wiring system. The obvious first step of course, would be to match the colors on the male and female pins but as usual on one pin there are no matches and on the other there are 2 possible combinations.

Any help would be appreciated and the MY or engine may not matter.

Thanks
 

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Hey Uber,

Welcome aboard to the W126 machine!

Uff, what a pain.

Let me take a look.

Please tell me the year?

You are mostly concerned with the 'female' connector, I surmise?


M
 

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Discussion Starter #3
Hey Uber,

Welcome aboard to the W126 machine!

Uff, what a pain.

Let me take a look.

Please tell me the year?

You are mostly concerned with the 'female' connector, I surmise?


M
Correct. The females are always the ones that seem to slip thru my fingers LOL.
I matched the difficult pair which had changed colors and only have a green pair left.

The male green could mate with the female green, which is my assumption, or it could mate with the green and black stripe, which for some reason is also vacant.

Do you or anyone else know if there are better wiring diagrams available for the W126?
I'm re-wiring the "Automatic Climate Control" circuit and the diagrams from the MB CD are awful. The complete system circuit is really what I need but the ones I have are a blur of discontinuous lines and unreadable component ID's. The sub-component drawings are ok for single components but tying them all together is like a game of pin the tail on the donkey.
 

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Discussion Starter #5
OK, here is X26 from the paper manual..

The color code of male plug 9 is sw/ws

Hope this works for you

MBL



View attachment 2604988

View attachment 2604989
MBL87560SEC, many accolades for your help.

The diagram you provided confirms that the Gn/Bk wire is not used and the Green male & female wires mate.

Do you have or know where I might find a wiring diagram of the engine harness alone, from the firewall forward? One again, this ties into multiple sub-systems and is the last step I need to perform to get this wired correctly.

This would also be a valuable resource for other owners who need to replace this because of shorts, meltdowns, or outer coverings that are cracked and hardened.

Thanks again
 

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Discussion Starter #6
MBL87560SEC, many accolades for your help.

The diagram you provided confirms that the Gn/Bk wire is not used and the Green male & female wires mate.

Do you have or know where I might find a wiring diagram of the engine harness alone, from the firewall forward? One again, this ties into multiple sub-systems and is the last step I need to perform to get this wired correctly.

This would also be a valuable resource for other owners who need to replace this because of shorts, meltdowns, or outer coverings that are cracked and hardened.

Thanks again
I'm sorry, I forgot to identify the specific year. It's a 1987 300SDL.
 

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MBL87560SEC, many accolades for your help.

The diagram you provided confirms that the Gn/Bk wire is not used and the Green male & female wires mate.

Do you have or know where I might find a wiring diagram of the engine harness alone, from the firewall forward? One again, this ties into multiple sub-systems and is the last step I need to perform to get this wired correctly.

This would also be a valuable resource for other owners who need to replace this because of shorts, meltdowns, or outer coverings that are cracked and hardened.

Thanks again

I'm sorry, I forgot to identify the specific year. It's a 1987 300SDL.

Hi there,

I am pretty sure this is what you need. It came from the Diesel Engines Manual 602, 603

MBL

IMG_4679.jpg
 

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Discussion Starter #8
Hi there,

I am pretty sure this is what you need. It came from the Diesel Engines Manual 602, 603

MBL

View attachment 2605172
You're the man, MBL87560SEC !

This diagram and the quality of resolution is exactly what I needed. I'm overjoyed that another all-nighter is unnecessary and I could be driving the car tonight.

A hundred thanks for your help.
 

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Discussion Starter #10
Here's a photo followup showing the wiring surgery, a handmade engine harness, and the test drive.
Everything worked without any sparks, flames, or explosions!
Thanks again for all the help, it really made a difference.

01_Wiring_Surgery.JPG
02_Handmade_Harness.JPG
03_Test_Drive.JPG
 
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