W124 harness issues

[mario andretti]

Just wondering if the crumbling loom of an m111 is the only harness issue in a w124. I am currently rebuilding my harness with new connections and wires but I am wondering do any other looms in the car suffer with this silly carry on.

 

[millo777]

From what I gather, all of the wiring looms in cars of that era are made with the same biodegradeable insulation. So far, only the engine bay looms have caused problems, due to the heat from the engine accelerating their denise.

 

[mario andretti]

Oh beautiful as this could kill a few w124s then over the next while.

 

[millo777]

I've never heard of the other looms causing problems. It tends to be the engine loom, and throttle body that need rewiring.

I have however had both wing mirrors on my w140 replaced as the wiring had disintergrated.

I wouldnt worry to be honest, there has been no indication yet that the rest of the electrics will cause problems.

Iif you'd ever owned a vw would think your current electrics were a dream.

 

[mario andretti]

Well hopefully it is only limited to the engine harness.

 

[mario andretti]

Interesting that any of the coaxial cables in the engine harness seem to be good.

 

[dinoy]

i thought it was mainly e320 models facelift where biodegradable was used. is this not the case and e220 e200 it applies too, and not sure 300ce is which prefacelift

 

[mario andretti]

Sorry must update my profile as it is a 94 220 coupe that I have recently bought.

 

[bolide]

W124 wiring looms elsewhere disintegrate: by the tailgate hinge on estates, through the rubber boot into the doors & anywhere else the wiring is stressed or flexed

On parts like wing mirrors & throttle bodies it's easy enough to rewire them. Tailgate & doors, ditto. The engine loom is a big undertaking

Nick Froome

 

[carat 3.6]

i thought it was mainly e320 models facelift where biodegradable was used. is this not the case and e220 e200 it applies too, and not sure 300ce is which prefacelift

Any m104 (except the 3.0), m111, and m119 engines, fitted to a w202, w140, w124, or r129, will at some point have engine harness issues.

 

[mario andretti]

Cheers as I am prepping the car for a long euro trip via Chernobyl and Moscow so don't want any wiring issues there hehe

 

[poormansporsche]

How comes the C280 W202 m104 is not known for looms dying ? Is it just that they are more scrappable and people dont really post about it ?

 

[carat 3.6]

How comes the C280 W202 m104 is not known for looms dying ? Is it just that they are more scrappable and people dont really post about it ?

The grey c class you saw today had that very problem Brett, it's just that it's not as popular as the w124.

 

[HoppoE320]

W124 harness rot

My E320 has the dreaded harness rot. The P/N of my harness is 124 440 32 33. MB still stock these, but the cheapest offer I have had is £1,550! There are a lot of reconditioned, and very substantially cheaper, harnesses offered in the USA, but these are for LHD cars. The equivalent LHD harness looks to me like 124 440 29 33 - this one looks like its got the square water-pump sensor pin, which I think marks cars after early-1995 - mine is late-95. Has anyone out there tried fitting one of these to a RHD car?

 

[hotrodder]

My E320 has the dreaded harness rot. The P/N of my harness is 124 440 32 33. MB still stock these, but the cheapest offer I have had is £1,550! There are a lot of reconditioned, and very substantially cheaper, harnesses offered in the USA, but these are for LHD cars. The equivalent LHD harness looks to me like 124 440 29 33 - this one looks like its got the square water-pump sensor pin, which I think marks cars after early-1995 - mine is late-95. Has anyone out there tried fitting one of these to a RHD car?

A few people have used LHD looms on RHD cars, there's a dedicated thread for 124 engine looms where it's mentioned IIRC, i've got a vague recollection that bit's of LHD looms (like the MAF) are way long http://www.mbclub.co.uk/forums/engine/67830-w124-engine-bay-wiring-looms.html

Personally i'd rebuild the origional loom or pay an auto spark to. Most, if not all, of the plugs are available from MB pre assembled with enough wire to reach the ecu. Some are dirt cheap, some aren't but at least if any of the plugs are/get damaged and/or gone brittle from heat cycling...
Si-Leck are a motorsport wiring company that have rebuilt more than a few MB looms. A search of the forum will find several threads where they've been mentioned, here's a recent one albeit about r129s and the m119 V8... http://www.mbclub.co.uk/forums/engine/193447-r129-m119-engine-wiring.html Dunoo whether a LHD loom from the States would be cheaper but at least getting yours rebuilt you know refitting it will be straightforward and painless

 

[harryk]

Hoppo, your price for the loom is way too high! Shop around: I bought my loom from MB in Dublin last month and it was under half that price once converted to STG!

Speak to Johnny at Bradys Dublin or email [email protected] with your chassis number

Tell them Harry from Derry sent you!

 

[coupe addict]

Reverting to the OPs original question, on the E220 the issue is less acute because the loom doesn't take such a hot route. However, there is a particular point on the loom which is at higher risk, which is where the MAF wiring is clipped to the back of the engine on the hot side. Insulation breakdown here causes weird random problems, but a Stanley knife and a roll of insulating tape are all you need to prevent it.