Repairing Your Engine Wiring Harness - Page 4 - Benzworld.org - Mercedes-Benz Discussion Forum

adamb321 · 04-03-2007, 05:38 AM

Quote:

Originally Posted by n0alpha

As requested by several people, here's a short DIY to repair your engine wiring harness so you don't have to spend $800-$1500 to replace it.

Take the cover off where you would replace the spark plugs to see the three wires (on a C280) that lead to the 3 coils. These wires are 12V DC, and are the most common failure points.

Picture 1 is a view of the part of the harness on my car that failed. Carefully cut off the outside insulation of the harness between the plug and where the harness enters a rubber section.

Picture 2 is a view of the harness after I removed the outside insulation. The picture is kind of fuzzy, but you can see the green corrosion on the wires and how there is no insulation around them...this is bad!

Picture 3 shows how I separated the wires and wrapped electrical tape around them, and then wapped more tape around both wires to hold them together. Be very careful to separate the wires entirely, especially in the plug and in the rubber housing.

Connect everything back up, making sure to have the air tube that crosses over the engine back in place, and then start her up. She should fire on all cylinders now, but if she doesn't then just jiggle the two wires around a bit hear the plug and rubber until it works.

Last step, to reset the Check Engine Light, turn the engine off and pull fuse number 32 in the fuse box on the driver's side of the car (LHD cars), and leave it out for about 30 seconds. Replace the fuse, turn the car on, and the Check Engine Light should be off.

Good luck!

can u please help me ive got a 94 built c220 that when i start it goes to stall and the engine is hunting revs up and down and get a noise from internally its hard to explain then u drive down the road maybe 5 mins and its running pefect but then if u turn the car off for 1 minute and try and drive off again it does the same thing again any ideas!!! i really need ure help

rcltrh · 04-20-2007, 06:10 PM

Anyone willing to share the name of a company or aftermarket retailer who sells 96- C220 replacement wiring harnesses? My local mechanic has determined that to be at least part of my no-idle and poor running problem. MB wants $1080 for the harness (wow 30 feet of wire) What a freaking rip off. I told him I'd sell it to the scrap metal junkyard in town before I'd pay them that for their own defective product. Is there a website for the NTSA where we could all write complaints about this ripoff? I bet MB did this on purpose knowing they could sell $1080 wiring harnesses a few years down the road. Grrr. Makes me really mad. Anyway, would love to know anywhere to buy a replacement if someone has knowledge. Thanks!

doin12volt · 04-24-2007, 04:23 PM

Anyone interested in a harness re-build service? I have been doing automotive electrical for the last 16 years, and I am a 1st class certified MECP technician.

I have all the supplies to do this, and i ONLY use solder and heat shrink tubing, NO CRIMP CONNECTORS!!!

Would $300 per harness and about a week turn-around time be decent?

What do you guys think, im just trying to help....

**n0alpha** · 04-24-2007, 06:47 PM

Quote:

Originally Posted by doin12volt

Anyone interested in a harness re-build service? I have been doing automotive electrical for the last 16 years, and I am a 1st class certified MECP technician.

I have all the supplies to do this, and i ONLY use solder and heat shrink tubing, NO CRIMP CONNECTORS!!!

Would $300 per harness and about a week turn-around time be decent?

What do you guys think, im just trying to help....

The biggest thing would be making sure you use high temperature rated materials, but if your work is clean, you use good materials, and offer some sort of warranty on workmanship, I think $300 would be a reasonable price.

doin12volt · 04-27-2007, 07:55 PM

Yes, I use STRICTLY Automotive grade wiring,(resistant to oil/gas/high temparatures) - and a warranty would be no problem, i offer a lifetime warranty on all of my work...Thats why i wont use those crimp connectors- they can and WILL go bad. I exclusively SOLDER everything. If anyone needs this service, just remove your harness from the engine compartment and PM me for an address....

tui0jst · 05-21-2007, 10:36 PM

1997 C280 140,000 miles. I bought the car from a dealer used. Is there a way to tell if the wire harness has already been replaced? The car runs like a top and I am just waiting for this harness to go bad.

junsoyao · 07-10-2007, 02:42 PM

I am confused regarding the wiring harness. Below is a link I found which sells the wiring harness for only $52.00. I am not sure this is the right one that you guys are discussing. Please advise.

Select Product

Thanks

OzC36 · 07-11-2007, 08:46 AM

No.

Yes, that is "a wiring harness". But that one is for the wiring to the fuel tank to indicate the fuel level.

Take a look at the link below for engine wiring harness part numbers:

Êàòàëîã

gordonese · 07-30-2007, 07:53 PM

I took my 1996 C220 into the dealer to have it serviced and see what was causing the "Check Engine" light to glow orange and it came back that I need a new Engine Injection Wire Harness, Engine Wire Harness, Engine Harness, (I have seen the same thing referred to with many different, similar, names). My service advisor tells me that to have it replaced I would be lookining at a total of about $2200, (parts, labor, and taxes).

Is this too much for this? I have seen others say it cost them only around $1000.
What would be my best bet, buy the part from the dealer and have another mechanic install it? Just have it done at my dealer, possibly ask another nearby dealer? I really am at a loss here.

Any advice would be appreciated, thank you.

benz rider · 07-31-2007, 06:31 PM

Quote:

Originally Posted by gordonese

I took my 1996 C220 into the dealer to have it serviced and see what was causing the "Check Engine" light to glow orange and it came back that I need a new Engine Injection Wire Harness, Engine Wire Harness, Engine Harness, (I have seen the same thing referred to with many different, similar, names). My service advisor tells me that to have it replaced I would be lookining at a total of about $2200, (parts, labor, and taxes).

Is this too much for this? I have seen others say it cost them only around $1000.
What would be my best bet, buy the part from the dealer and have another mechanic install it? Just have it done at my dealer, possibly ask another nearby dealer? I really am at a loss here.

Any advice would be appreciated, thank you.

YES! that is waay too much. it's proven time and again that the dealership charges too much and takes too much time. find you a reputable indy MB mechanic that cares about what they do and who know their stuff about MB. with reasonable prices.

good luck.