W124 Engine bay wiring looms

[taleff]

Hi all,
I worked at MBAU for 10 years (we have RHD cars like UK) and it was a common problem on many models for a few years, especialy the cars with higher under bonnet temperatures. There is an after market company called Delphi that makes new engine looms that dont crack. You need to get the part number from the original loom. I have a 1994 e220 W124022 and found a good one at a wreakers, the part number on it is M124 543 3533. I have seen some of them on ebay. I hope this helps, Good luck.
Regards taleff
Ps- My C180 W202018 has the same problem, often it is not found until a manifold or cylinder head is removed, disturbing the wiring loom.

 

[Creativeblock]

Hi Guy's,
This is my 1st post in the forum, I have a brand new Mercedes loom for sale, its for a 1995 E220 part no MA124 440 39 33, it will come with the cash sale invoice from Mercedes, £400, brought 02/03/17 but never used, I have decided to renew & transplant the engine from my 300E instead.
Regards,
Mark

 

[Williamwoo]

Hi Guy's,
This is my 1st post in the forum, I have a brand new Mercedes loom for sale, its for a 1995 E220 part no MA124 440 39 33, it will come with the cash sale invoice from Mercedes, £400, brought 02/03/17 but never used, I have decided to renew & transplant the engine from my 300E instead.
Regards,
Mark

You're probably better off advertising it in the Parts for Sale section, I would have thought.

 

[mcbcelik]

Thanks guys, yeah a part no. will come handy.

 

[Jetspanner]

Hi all , new to the Club , thank you for accepting me , also new to Mercs ! I did it , 1995 w124 E220 C ! . ref to electrical harness , have we isolated any areas that might be more susceptible to damage say due to chaffing or exposure to hi/low temps ? thanks .

 

[mbciho]

can someone sticky this thread as it's a recurring problem?

 

[Williamwoo]

can someone sticky this thread as it's a recurring problem?

It has been for ages I think.

 

[iggyb]

Hi all! So I've almost removed my wiring loom in my e280 ready to send to Si-Leck and run into one snag. There is one plug that I can't seem to find any mention of before that disappears deep behind the back of the engine, against the firewall. I cannot reach it to unplug! Does anyone have any bright ideas before I just snip it off with the intention of soldering the new loom back on when it arrives?

Fyi, last pic is taken from passenger side (RHD) over the battery/ECU.

 

[Martyn_n]

Hi all! So I've almost removed my wiring loom in my e280 ready to send to Si-Leck and run into one snag. There is one plug that I can't seem to find any mention of before that disappears deep behind the back of the engine, against the firewall. I cannot reach it to unplug! Does anyone have any bright ideas before I just snip it off with the intention of soldering the new loom back on when it arrives?

Fyi, last pic is taken from passenger side (RHD) over the battery/ECU.


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I am pretty certain that it is for the crankshaft position sensor. persevere on getting it off properly rather than cutting it as I believe it may be a screened wire.

 

[iggyb]

I am pretty certain that it is for the crankshaft position sensor. persevere on getting it off properly rather than cutting it as I believe it may be a screened wire.

Yep I think you're right. Probably the only one that doesn't actually need replacing. After about half an hour of trying to lever it off with a long screwdriver and some bbq tongs I had a bit of a meltdown and yanked it in a rage. Lo and behold it came free. There's no way I'm going to be able to get the new one back on and it's not going to start without it, I reckon I might have to call a pro out here to get underneath.

EDIT: Maybe I would have had an easier time if I removed this (aircon?) hose?

 

[Martyn_n]

IIRC when I reinstalled the connector on mine I could just about reach it enough to hold it over the connector and used a long socket extension to tap it down from the top. I hope that makes sense. I don't recall having to remove any hoses.

 

[iggyb]

IIRC when I reinstalled the connector on mine I could just about reach it enough to hold it over the connector and used a long socket extension to tap it down from the top. I hope that makes sense. I don't recall having to remove any hoses.

Ok thanks. I could barely fit a long screwdriver down there but will give it a go.

 

[wrdcc01]

Straightforward way is disconnect the battery earth, get under the car and undo the starter motor. Just move it back you don't need to remove it's wiring. The sensor is right above it and easy to disconnect then.

 

[iggyb]

Straightforward way is disconnect the battery earth, get under the car and undo the starter motor. Just move it back you don't need to remove it's wiring. The sensor is right above it and easy to disconnect then.

"Under the car." I fear this cos I am a noob.

 

[iggyb]

New harness back in! Just wanted it to be known that Simon from Sileck down near Folkestone has done an absolutely amazing job on this and the whole thing is better than even a brand new one I'm sure. It hasn't quite sorted out my misfire/rough idle problem but the whole thing runs smoother and it's sorted out a few niggles elsewhere. If only for peace of mind and to avoid inevitable future problems I can thoroughly recommend you send your wiring harness down to Simon to get sorted out.

 

[Meliisa]

Thanks,
That helped me a lot.

 

[multigrade]

I've just done the same thing, fitted a new harness from Si-Leck. Hot tip: there's no need to get under the car and move the starter motor. Instead, remove the throttle body, crawl on top of the engine and from there, you can see the crankshaft sensor socket, and fit the plug fairly easily.