Thanks in advance for your opinion and suggestions. I have a 1995 S320, 77K. For the past several months, I have been getting numerous engine codes when the check engine light comes on. I can reset it, then it maybe 10 minutes or 10 days later it will reappear. Today, i took it to my MB repairman. He noted that it needed an engine wire harness and quoted me a price of around $700 for the wire and then extra for labor. I did notice that the connectors (actually the wires at the edge of the connectors) had bare wires showing. Thus, I think that under certain conditons, rain, etc. that could be the reason for the misc. codes. He also told me this was a common problem. Any suggestions, comments? And where should I get the part? Does the $700 sound legit? Thanks

 

the injector wiring harness and air mass sensor wiring harness are usually defective. we got service measure (recall) on this.

you must replace them together. an instruction is included together with a small tool for removing the pins.

 

I recently purchased my 5th MB, a clean 1994 S320 w 84K mileage. I'm a retired fellow and was shocked today when a mechanic (charging my AC)
told me the my wiring harness would need replacement in the near future
and quoted me a repair price close to what I paid for the car...$3400.!
What alternatives do I have re the long ago recall you mentioned in 2005 for the injector and air mass sensor service measures (recalls) the MB issued. Also, where can I purchase this (or these) harness (s) when & if I need it. Is there anything I can do to solve or alleviate this possible pending problem?
Any advice will be appreciated...
Thanks,
Don

 

The years 1994 to 1996 used biodegradable plastic insulation on the wires. Unfortunately this degrades quickly and/or becomes brittle too, so by now a lot of cars made between these years really need a new wiring harness in the engine bay as the wire insulation literally can fall off when you touch it.

For many cars the insulation is still on the wires in the engine bay by virtue of the fact they are close to other wires and have cable ties round them too or have another sleving on the outside, so problems are not always quickly apparent unless you have a good look around. They often first show up as random electrical problems (often when it is wet outside as water is causing things to short on wires where the insulation is missing).

Mileage seems to play little part in how quickly it degrades, so it can happen on high or low mileage cars.

For that reason it is a good idea to avoid W140s made between 1994 and 1996 given they are 14 to 16 years old now and over time I expect almost all to suffer from this problem, if they are not already suffering form it to different extents. It can affect all wires on the harness so full replacement is the only long term fix, though this will cost more than the cars are now worth on the second hand market.

If anyone is looking at a W140 I would suggest only looking at cars made in 1997 or later.

$700 sounds low, I was under the impression you are looking at around £2000 GBP for an engine bay harness, fully installed, which is aprox $3200. It is a big job.

 

jrhilton is right about those years. That was the timethat Mercedes tried to use "environmental friendly" plastic in their wires. It was a fine idea, on paper and most wires held up fairly well but, the wre harness goes through things that most other wires never have to deal with. Engine heat and plastic usually dont mix well and the wire harness is a major component to the car. Everything from flickering dash lights, components working stop working then work again through out various components, or the car plain dont work. And these things degrade also jus due to time as any wire does. If tou want a W140 and not worry about it 1997+ is the way to go. If you just want the 194-1995 or fidn a killer deal, then try to find one where that thin was replaced recently. If not, find an indepent mechanic or online place (I use autohausaz and not had problems with them or parts at all) and find one. On autohausaz they ask $629 for the Genuine OEM one. Partsbin, partstrain, benzbin all are usually around same price The dealership will cost you about three/four times as much for the exact same part and quality.

 

I now view the mechanic's quote of approximately $3400. as quite high.
My harness (140 540 69 32) through Parts.com is available at $410.
Depending on the labor hours needed (at $46. per hr. in my area) I am looking at a total cost of approx. $700.-800. dollars.

 

Correct me if I'm wrong but isn't 1405406932-22 >just< for the fuel injection system and MAF wiring for which I think there was a recall? $3400 sounds like the whole lot to me, and maybe even the wiring around the gearbox too?

Double check, every wire in the engine bay could need to be replaced over time, it is a big job if done fully. Ask them what the $3400 really is for. I have heard on some cars almost every wire in the bay needed changing, even the wiring to the 38pin STAR connector!

 

this is "only" the Fuel Injection System wiring harness that Parts.com sells for $410. (Part # 140 540 69 32) Seems solution enough to me. Your comments?
(Hopefully the attachment will be added to show the harness.)
Don O'C

 

I should have added that I do NOT intend to use the shop that quoted me $3400. as their hourly labor rate is $85. and locally my shop charges $46.

 

Its a straight 6. Relatively easy compared to an 8 or worse yet, a 12 cyl car.

3400 must be a stealership price; an indy can do <much> better.