Ok, I've searched all the threads about the wiring harness but can't tell if mine is new, old, or faulty. I've spent considerable time and money with my '95 C280 in the shop trying to fix a rough running condition with no success. The symptom is, decelerating, and then accelerating, usually during a right hand turn, one of the cylinders drops out. I turn the car off and start it again and it works fine.

1) Where under the hood can I check the condition of the wiring harness?

2) Is it wrapped in cloth tape? That's what mine looks like if I'm looking in the right place.

3) Where are the ignition coils? I've worked on my own cars a lot but feel stupid that I can't find the ignition coils or spark plugs on this crazy German car.

Help please...

 

I took mine into the dealer to get a bunch of work done recently and asked a MB Tech about the wiring harness on my car, he said he already looked at it and that I have the updated one so I don't have to worry about it. My advice is to take it in and have a tech look at it and tell you what's up. I'm sure they wouldn't have any problem telling you about it and pretty sure they're not gonna charge you for it.

 

"Not going to charge you for it" - damn, I gotta move to Texas.

I just replaced a harness on my 95 C36. I took it to a dealer first to make certain that was the culprit - but I was fairly certain it was before spending $100 for them to tell me so. Just wanted to make sure before replacing myself.

Your best bet is to take your car into a dealer to have them inspect the wiring harness because you suspect it could be failing. Then if they think the wiring harness needs to be replaced, decide whether you're up to the task of replacement or whether you want to spend ridiculous amounts of money for labor.

One of the most evident places the harness may be disintegrating is around the MAF sensor (on your air intake tube - left side when standing over the engine compartment). That wire is connected to the rest of the engine wiring harness - as are the coil packs which are located under the plastic cover bolted to the top your valve cover. Usually the iginition wires located under that cover show signs of disintegration as well.

Installation of a new wiring harness is relatively straightforward BUT tedious stuff and some plugs are very difficult to install due to cramped conditions - of course, this may be different with a 280. A search on wiring harness installation should uncover some good hints. Club202.com has some useful posts as well.

Best of luck.

-drags

 

anyone have any pics of good vs. bad to show as examples for us newbs?