grober
MB Master
Here's a picture of the loom to give you an idea what to look for. Mercedes r129 SL500 (93-95) 500SL Engine Wiring Harness | eBay
Basically its all the low tension wiring associated with the engine sensors and injectors and low tension side of the ignition terminating in a large connector leading to the engine ECU. Does not normally include the high tension side of the ignition the alternator/charging/starting cables or any brake/asr circuitry. The engine wiring loom is the most vulnerable since its in close proximity to the hot engine block and its heat that accelerates the insulation degradation.
Basically its all the low tension wiring associated with the engine sensors and injectors and low tension side of the ignition terminating in a large connector leading to the engine ECU. Does not normally include the high tension side of the ignition the alternator/charging/starting cables or any brake/asr circuitry. The engine wiring loom is the most vulnerable since its in close proximity to the hot engine block and its heat that accelerates the insulation degradation.
millo777
MB Enthusiast
- Joined
- Mar 9, 2011
- Messages
- 1,250
- Location
- Swansea, Dubai, Riyadh
- Car
- 1997 W140 S600L/2003 S211 320cdi
Is there any concensus on which model years were affected on the W124 yet?
For the W140 it seems well established that all cars up to modle year 1995 were affected, some 1996 cars and 1997/98 are all o.k.
From what I've read, it seems to be mainly 94/95 cars that are most affected? would that indicate it is a post facelift only issue? or only on 16v/24v engines?
Just curious more than anything.
For the W140 it seems well established that all cars up to modle year 1995 were affected, some 1996 cars and 1997/98 are all o.k.
From what I've read, it seems to be mainly 94/95 cars that are most affected? would that indicate it is a post facelift only issue? or only on 16v/24v engines?
Just curious more than anything.
grober
MB Master
MB realised the error of their ways in early 96 I believe but just like the later "which cars are galvanised" issue its sometimes difficult to pinpoint exactly when the changeover occurred in relation to any individual car as the changes to the wiring would phased in for different models. I don't know who manufactured the actual faulty looms but its rumoured it was our own Joe Lucas who manufactured the insulated wire used. AFAIK none of the earlier single cam 4 AND 6 CYLINDER ENGINES were effected.
Last edited:
ngenius1
Active Member
- Joined
- Jul 20, 2007
- Messages
- 197
As Williamwoo, i remade the loom for my 320 coupe (k reg).
I used rubberised mains cable of the same gauge as the original.
Replaced 1 cable at a time, soldered and shrink wrapped.
I also managed to get into the sealed ends with a sharp utility knife.
Self amalgamating tape and cloth tape to give it the factory look.
Has been perfect for over a year.
Not to hard to do, just takes quite a while.
Have a few pictures somewhere, will post if i find them.
I used rubberised mains cable of the same gauge as the original.
Replaced 1 cable at a time, soldered and shrink wrapped.
I also managed to get into the sealed ends with a sharp utility knife.
Self amalgamating tape and cloth tape to give it the factory look.
Has been perfect for over a year.
Not to hard to do, just takes quite a while.
Have a few pictures somewhere, will post if i find them.
BoyracerAU
Active Member
Check your sensors for signs that the insulation is breaking up at the connectors. And check the date of the loom's manufacture, revealed on a white tag attached to the loom located in the battery compartment. Incidentally, my 1996 car's loom was dated 1993, various other looms in the car show 1994.
Druk
Gone but not forgotten - RIP
- Joined
- May 28, 2004
- Messages
- 5,300
- Location
- Not far from Edinburgh.
- Car
- 2011 S212 E350CDi. 1981 R107 300TurboDiesel.
Just to put the cat among the pigeons I've got in the garage the 300 24v diesel engine that came from the '95 E300TD that had a dashboard fire when it was in the possession of Trapperjohn.
Cursory examination of the engine wiring loom has shown it to be severely corroded in the insulation. I might start a new thread on this when I've got it all apart, but for now I wonder if the cause of the fire was faulty wiring?
Not to worry anyone of course...
Cursory examination of the engine wiring loom has shown it to be severely corroded in the insulation. I might start a new thread on this when I've got it all apart, but for now I wonder if the cause of the fire was faulty wiring?
Not to worry anyone of course...
Druk
Gone but not forgotten - RIP
- Joined
- May 28, 2004
- Messages
- 5,300
- Location
- Not far from Edinburgh.
- Car
- 2011 S212 E350CDi. 1981 R107 300TurboDiesel.
If the wires are bare there then I'm afraid they will be bare elsewhere and probably inside the engine cover at the coil packs which is where the most expensive damage occurs unless it is sorted.
trapperjohn
MB Enthusiast
Bugger. Sorry about that Derek. I was always sure that my diesel engines were not to be bothered with loom issues. I'll leave well alone on my current flock but keep at the back of my mind that I could have issues too.Just to put the cat among the pigeons I've got in the garage the 300 24v diesel engine that came from the '95 E300TD that had a dashboard fire when it was in the possession of Trapperjohn.
Cursory examination of the engine wiring loom has shown it to be severely corroded in the insulation. I might start a new thread on this when I've got it all apart, but for now I wonder if the cause of the fire was faulty wiring?
Not to worry anyone of course...
As to the fire. It was fairly obvious it was a wire issue. The ABS lamp wire appeared to be the culprit. It was heat damaged right from the back of the speedo cluster through the bulkhead and into the fuse box taking prisonsers as it went on its way. Just where the heat started from and what the exact cause was will be a mystery for ever now.
Druk
Gone but not forgotten - RIP
- Joined
- May 28, 2004
- Messages
- 5,300
- Location
- Not far from Edinburgh.
- Car
- 2011 S212 E350CDi. 1981 R107 300TurboDiesel.
Indeed!. Although to qualify what I posted I have no knowledge of the 220 engine arrangement, only the 320 HFM, so yours might be different. It does need further investigation nonetheless.
Druk
Gone but not forgotten - RIP
- Joined
- May 28, 2004
- Messages
- 5,300
- Location
- Not far from Edinburgh.
- Car
- 2011 S212 E350CDi. 1981 R107 300TurboDiesel.
As per the email, don't worry about it John. If the engine ends up where it was intended the wiring will all be renewed anyway as a matter of course.
to be honest there's a few things that have already come up with the 220 since I bought it on friday that I'm not really that happy about. I have time and energy for a certain amount of fixing, but I think it's going to be a case of selling it on as I can't afford to spend much time and money on it right now. It was very cheap, so I only have myself to blame, but am surprised by the amount of little things that need looking at on these W124's considering they're supposed to be well made!
watch this space for an ebay link!
watch this space for an ebay link!
d w124
Hardcore MB Enthusiast
- Joined
- Dec 30, 2008
- Messages
- 12,491
- Location
- london
- Car
- w124 3.6AMG styling E320 S124 Lorinser styling
Don't blame the car if you bought a dog,as you say it was cheap but there's a reason behind it.Whoever had it before you,did not care about it hence it is in that state
As they say,nothing is more expensive than a cheap merc Lol
As they say,nothing is more expensive than a cheap merc Lol
Yeah, I know. I just feel like a plumb enough as it is! to be fair I knew it would need work, but The wiring loom thing is just something I don't have the time or money to fix right now. I didn't realise until now that it was such a big problem. I'd looked into them, but this didn't enter my radar for some reason.
Not the best day of my car owning life.
Not the best day of my car owning life.
Druk
Gone but not forgotten - RIP
- Joined
- May 28, 2004
- Messages
- 5,300
- Location
- Not far from Edinburgh.
- Car
- 2011 S212 E350CDi. 1981 R107 300TurboDiesel.
Shame you've bought a duffer but good you came on and found out about it before too late. A lot of the wiring issues these cars have are still coming to light. Initially we though they would only apply to the larger petrol engined cars but it seems that other variants are now becoming affected. It's an education for us as well. Good luck to you. 