We have a 1994 C280 and sometimes it won't start. I've noticed somtimes just before I shut it off, the rpm will be above 1000 or flucutating above 1000 to 1500. if I shut it down when it's doing that, later it's hard to start.

I took it to the authorized repair shop we've been going to and he wound up trying to tell me it was the engine wiring harness!

Has anyone heard of Mercedes having problems with wiring harnesses or anything that sounds like this problem?

yes yes yes yes
 

Ya, Ya, Ya
do a search on this common subject.
check your spark plugs and wires.
do a search and be proactive.
good luck!

This is common for them to have bad wiring harnesses, especially after 7 years. GO to the dealer, sometimes they will do it as a courtesty if your car has less than 120K miles because SO many of them have gone bad.
Luckily mine is still good... knock on wood!

DavidCKLASSE
 

I purchased a package of 1/2 inch split loom
(NOBLE wire & terminal co.
springfield, oregon) at the hardware store.
This is the black plastic tubing that is corrugated and split down the middle.
My idea is to install this over my wire harness
anywhere that it can be applied as a way to
shield against elements that cause deterioration.
What do you think of this idea? or anybody's opinion?
Thanks

I think that is very smart. Consider it preventative maintenance. I have thought about this, but I don't know where my wiring harness is?

Don't know where it is?

It is a giant mass of wires that runs through the engine compartment. Look for it again, it is kind of hard to miss. Check insulation to see if it is carcking or deteriorating.

Ali,
but there are all sorts of wires all over the engine compartment. Where in the engine compartment??? Over by the computer stuff in the passenger side rear under that panel?? Or where?

David,

Find a wire on the engine, any wire. Think of it as a branch, follow it to the nearest trunk. You've found a harness. Follow that trunk till it reaches anothern. You've found more harness.

So the wiring harness is not just one harness, it is a mass of harnesses to other harnesses and so on?

All the wires under the hood are collectively known as the harness. Like Mike said, find any wire and follow it to more.

So would it be agreed by all that maybe adding some extra insulation to wires where possible is in fact a good idea? We might only be postponing the inevitable, but definitly better than not.

This sounds a little crazy to me. The problem in the wiring harness is not so much that the sheath needs to be insulated, it's the actual insulation which surrounds the individual wires which goes bad. The wires aren't insulated from each other properly. If you can individually add extra insulation even where possible it won't really solve the problem. It's where the wires are bunched together that's the problem. I looked at the alldate website and all I found was a TSB 91_072 issued in Nov 1995 for the airbag wiring harness.

Kuan

now we are getting somewhere!
 

Kuan, good point. Thanks for the TSB on the airbag.
I always figured it was the engine heat that
accelerated the deterioration of the 'black
'fabric' tape that is wrapped around the
wire groups. I deduced that once that
outer tape was dry, brittle and broken open, the
next phase was the individual wire would
be exposed and the wire's cover (plastic
sheath) would deteriorate leaving bare metal exposed.
I assumed it was the bared wire (metal)
that caused the engine etc. problems.

You seem to suggest that basically, the individual
wires, tape wrapped or not, have the problem
of their sheaths falling apart. Or are you
saying that the wires are not insulated
against each other's electrical current?

Having read archives on the subject, it seemed
that sheath deterioration and bare metal wire were the culprits. Although the source and cause of deterioration
was never mentioned other than 'age and miles'.
I'm interested in finding out.
Thank you all if you have any comments.

Harness repair by MB?
 

I've contacted MBUSA and they're acting like they've never heard of this and are unwilling to discuss repair.

From what I've researched this problem affects only a few year models harnesses produced by a certain vendor. That vendor's harness was discontinued when the problem became apperant.

I think it's unbelievable that MB would allow this problem to exist without at least notifying owners, much less a recall! The breakdown of insulation and bare wires could very possibly cause an engine compartment fire!

I'd like to know more about the post that said"

<sometimes they will do it as a courtesty if your car has less than 120K miles because SO many of them have gone bad.>

If you've had this done, or know someone who has please e-mail me at Ryszard@csi.com!

Search
 

R....Z,
Do a search on the issue. Try to search the term
wireharness for last year's archives.
I know that Benzmac ascertained this as a common
problem and some members have posted about
courtesy repairs, some have posted your same
experience,
It is advisable to contact different dealers since they all
operate differently.
Start writing letters to MBZ.
Good Luck. Keep posting your results.
Eventually threaten them with legal action
after you build a case with documentation.
That usually inspires some motivation.
The next step is to work on the terms.
I'd recommend MBZ pay labor and material.