Legoinsaniac

For the past month or so, I've been experiencing several tell-tale symptoms of a fried wiring harness. Slowly but surely, these symptoms were growing and becoming more frequent. I had intermittent ABS and ASR lights, as well as occaional idle stumbling, surging, and even stalling. So I tracked down an upper wiring harness from a forum member over at mercedesshop.com for the price of $475 shipped. (Thanks Ebennz!). My local dealer wanted $735 for it. Today I pulled out the old harness and replaced it with the nice new one. It only took me 2 hours, including time to clean up the engine while I was at it. Now the car idles soooooo smoothly! I really can't believe it. No warning lights either!

I took some pictures of the old harness so you can see some of the degraded wiring. After looking at the wires, I can't believe the car was running at all!

BTW, this is the 2nd time the upper harness has been replaced in this car's life.

Legoinsaniac

Why am I suddenly not allowed to post attachments?

GORBETTTEAM

bacause they're too BIG. reduce the size please.

Legoinsaniac

Here we go. Apparently the attachments option is down for a while on MbWorld (https://mbworld.org/forums/announcement.php?f=28)

GORBETTTEAM

wow...it does look bad...you said thsi was the second time this vehicle had wiring replaced when the previous replacement occured? just curious.

eolon

Now you have to do the lower harness, too.

Best Regards,


e

.::.

Koolwipski

Was it a hard job? I have a 1992 400E that needs the upper harness changed as well. I have a guy that will do it for $900.00 (parts & Labor). If I can do it myself in 2 hours for $500.00, I might give it a shot.

I keep having idle problems and the oil pressure gauge keeps jumping around.

Any difficult things I need a heads up on?

Legoinsaniac

It's definetly something you can do yourself. The only tools you need are an allen wrench, a phillips-head screwdriver, and an 8mm socket. All you have to do is remove the air filter housing, and then start unplugging. I would recommend taking a couple pictures beforehand to see where the wires run, so you get it right when you try to install the new harness. Everything else is self explanitory. You really can't plug anything into the wrong spot because the lengths of the wires only allow them to reach a certain place, and the wires that go the injectors are clearly labeled 1,2,3...

Good luck!


GORB- the previous owner replaced the harness in 1999 at 78,000 miles, along with rotors, pads, cooling hoses, a/c stuff, and some other odds and ends....that was an expensive bill! The car now has 180,000 miles on it, so it looks like these harnesses last around 7 years/80,000 miles.


Oh, and I've already ordered a lower wiring harness, so I'll post after I do that one too. It's supposedly much harder to replace than the upper harness.

Koolwipski

Where can I get one of these wring harnesses for $475? I went to mercedesshop.com but could not locate the part. Thanks. steve

Legoinsaniac

I found someone that was selling a spare harness for a 92 400E in the classifieds part of the forum. I just got lucky. You'll have to look around to try and find the best price.

G Man

Mine looked exactly the same at 59,000 miles, and the lower harness was in identical shape.

1995E420

hey guys wheres a good place to score on one of these wire harness?!?!

kwb210

I just got a price for engine wiring harness for my 1993 300CE: $899 and that was on sale! Any one have other pricing?
Also, why would you EVER have to replace a harness a second time? Certainly you are not putting on the same degradable one. Am I missing something? The new ones or replacement ones are not made of the same material.
kurt

Legoinsaniac

I'm not sure on pricing for the 300's, but I do know that their harnesses are more expensive than the V8's, for whatever reason. Just keep looking around; if $899 is the best price you can get, then you really don't have much of a choice. My harness needed replacing a second time because the harness was never upgraded for the 400's and 500's. The new ones still use the same biodegradeable material as the ones from the factory. Retarded, I know

Luckily for you, your replacement should be a one-time deal.



And if anyone was wondering, I got my lower harness and installed it a few weeks ago. This job was harder than the upper harness, but I'd still say it's a simple DIY. Only basic tools are needed--phillips screwdriver, a collection of sockets (17, 13, 10, I think?), extensions, and a swivel joint is vital. You don't need to remove anything to get the old harness out EXCEPT for a shield that protects the starter. Other than that, it's just a matter of figuring out the proper assembly of socket, extension, and swivel to reach the hard-to-get bolts. I used some twine tied to the old harness to "remember" the proper path. More twine is also necessary to get the new harness up through the small access hole into the CAN-box area. Total time was about 4 hours. AND guess what! My oil pressure gauge now works!!

Koolwipski

Sounds Cool. My oil pressure gauge jumps frm 3 to 0 all the time while I am driving. This is part of the "lower" harness? My upper is fried, I know b/c I took a plug off, shook it a little and insulation started falling out from the outer cover. I am also getting false codes for the throttle actuator.
I need to get these repaired;
however, i am seriously thinking about selling the car. I am in San Antonio, TX if anyone is interested. New trans, tires, A/C, window motor, Alpine, bla...bla...bla... hard to let go, but I got too many irons in the fire right now.

bluecoupe

I was reading another thread last night (check engine light) & one of the guys mentioned that he had managed to get MB USA to provide him with a new harness.

This is the firs I've heard of someone actually getting a harness out of MB, who typically deny all allegations of faulty wiring harnesses - claiming that "your issue is the first time we have heard of this"....

Has anyone else had this kind of luck with MB USA?

I have ordered a DENSO harness for my 1995 E320 coupe & expect a $1000 final bill for the harness / instllation (no time to do it myself), so I'd welcome any tips.

The picture posted in the thread above SHOULD be all the proof we need, right...?

vix

were are these wires/harness located on the car?

Koolwipski

I am goin to give it a shot. I did some research and found a site that deals with nothing but the MB faulty wiring harnesses. it has a link to the NHTSA (Saftey Admin) where you can make a complaint.
http://users.adelphia.net/~infoage1/...1991_1996.html

I am going to file a claim against MBUSA on this issue. I will let you know how it turns out.

natural_person

On another MB site:

http://www.benzworld.org/forums/w124...sponse-mb.html

Brian McL

I badgered MB Canada until they agreed to supply me with a replacement harness for my 94 E320.....but it had to be installed by my local dealer in Ontario...who said "we have never seen one of these fail"....liars. BTW..the dealer tried to get 5 hours out of me to install it....we settled on 2 ...it probably took them 1 !!

DarkHand

Finally Bit the Bullet and picked up the upper harness: Phill wanted 899 for it I was able to get it from the local dealership for 860. Once it came in when to the shop and actually went in with the mechanic in changing the harness. It does take 2 hours and when it was all said and done finally found the culprit of my high speed shutdowns. The connection that goes to the ignition coils: insulation was ed on all 4 wires across the board. Also changed the overload relay as it was smoked also.

Suffice to say my E320 runs great now..
Next project will be the lower harness when I can actually find the part number for it....

Johnny K 500

Has anyone had dealings with " Keep it clean wirung".I need to re-wire my 94 E320 wagon and I saw their ad.
Thanks
John

jvalenz75

hello there, I just joined this website and need help. I am looking for someone locally in san antonio who is a trusted and good mechanic. I have a 1994 E420 in which needs to have the Wiring Harness redone. please help

XJguy

Buy correct harness on ebay (there are several for the W124), look on youtube how to change it out. Its very, very easy if you are at all good with your hands and have very basic tools.

vahidhashemi66

I have a w124 220E 1994 and I want photos under hood and check wiring .