Another way to tell if your wiring harness has turned crispy. This is on a 92 400E with 133Kmi and no evidence of replacing the harness (VMI or the records from the last few years)

I was concerned that the harness may be the cause of problems since I was getting the ASR going into limp home mode, also the ground wire that comes off the harness under that air cleaner looked cracked. I pulled all the codes and figured I'd see what showed up when I start to drive it. (I'll post codes later when the car is on the road if anything reappears with the harness replaced)

But, on going through some other items in the car I figured I'd see if the insulation was craking on some of the wiring. Lets check one of the temp sensors twards the front of the engine (figured I'd slit the overwrap to see the individual wires). Give a light tug on the body of the connector and it split in two! Pressed on the release tabs on the sides of the connector and they both snapped off!!!!

So looks like I need to replace tha harness. Hopefully that will cure the flakey codes.

Now I'll fix that as well as small rust spots on the doors. I should have it on the road in a couple weeks

Paul

Good job, Paul! Please keep us "posted" as to how the job goes and its results.

I have some crispy insulation and have had about 3 or 4 occasions of going into "limp home", always when cruise control is engaged. Since they've only happened about once a year, I haven't done anything about it yet, but if a new harness for $400 would cure it, sign me up!

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Steve
'93 400E

My 93 400E required a smog test. It failed, so guess what the first thing we needed is a new wiring harness. ($1500.00 thank you, next!) Then it just barely passed the smog test here in California.
Now I've noticed the car misfires when hot and won't start when warmed up. I can see the plug wire arcing to the engine in the front so I hope that will fix the misfiring/lack of power.
Looking at this site I am hopeful that a new fuel pressure regulator will fix the warm starting problem. I may have needed a wiring harness, but I think the plug wire problem is the real culprit.
After the wiring harness set-back, I'm hoping that I can fix the plug wires and install a new pressure regulator.
Is there anything I should watch-out for when I tackle these tasks?
The car has 180,000 miles and the engine is "solid"
Thanks in advance for any advice.

among the things i've done to my 400e, is to replace the main engine wiring harness.

car is a '92, it has 92k, wiring harness is trashed.

all the stories you hear about the wiring degrading and crumbling in your hands is true.

my ground wire's insulation was all cracked too, this was nothing compared to the rest of it.

morozzi, if you have 133k you're way overdo to change it.

i was a bit paranoid on taking the car very far because i didn't want this mother to totally die on the road.

i paid [stealer] $530.00 for the harness, part # 124 543 88 32. i bought 2 of them.
my dealer cut me a break on the install also $120.00.

i think it only took the tech about 40 minutes to do it.

i feel car is more responsive now.

member infoage1 is requesting people send them to the nhtsb for examination.

infoage is a regular over at 500ectasy.com.

he's really pushing hard to get some to the fed.

he said only 2 have been sent in and they weren't too bad.

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*92 400e 124.034, SOLD

*92 300e 124.030, SOLD

$1500 is way high. I bought the harness from Caliber motors (which advertises in the mercedes club publication "The Star). From memory the harness was about $300. The replacement was easy, taking 2 or 3 hours for a first timer, examining things as you go. Just lay the new one on the old one and do one set of connectors at a time and swap in the new one. I'll volunteer to do anyones wiring harness local to me for a price much lower than $1500

Paul

morozzi

part # 124 543 88 32 current retail is $660.00

next time, i'll change it myself to

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*92 400e 124.034, SOLD

*92 300e 124.030, SOLD

Incredibly, it took until 2007 for mine to fail - 15 years. Still, this is not an acceptable situation - I have other cars with harnesses as much as 30 years old with no signs of brittle and broken insulation on the main harness.

Anyway, I am most of the way through with the installation of the new harness. No big deal, really. I'm guess no more than 90 minutes to do the work in a cold Wisconsin garage with bad lighting.

Incidentally, the list price on this harness (124-543-88-32) is now 665.00. I paid 545.30. Be careful - my local dealer told me the price was $796.00.

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2003 AMG S55
http://farm3.static.flickr.com/3414/...5813f01a_s.jpg