How Screwed Am I? (E420 w/ pictures) - PeachParts Mercedes-Benz Forum

dproudfo · #1 09-28-2008, 04:47 PM

Well, after having some problems with my car's idle (nothing major yet) I thought I'd give my '95 E420 a closer inspection of its wiring harness. It hasn't been replaced (to my knowledge) and the car just turned over 90k. Below are links to pictures of the areas of concern to me with the cracking of insulation and exposed wire in some places. I guess my question is, based on the pictures, how long do you think I have before things start going downhill quickly? New harness is around $650 last I checked and if I can wait a year that would be ideal. (Keep in mind that I'm in MN and the winters up here can get down to 20 below.)

Also, notice the dust in the pictures, I've had the car for the last 6k miles and it looks like it was garaged in a barn. Would you think that there might be Mass Air Flow sensor problems with all the dust? (considering cleaning it but am apprehensive about screwing with it and making my problem worse. Aside from the idle the car runs perfectly)

Pictures:

Guide Picture

Close up of area 'A'
(I didn't snap the plastic sheath off in the picture, it was how I got the car originally)

Close up of area 'B'

Close up of area 'C'

stevebfl · #2 09-28-2008, 06:11 PM

You were wise not to touch it.

I've replaced scores of harnesses and the worst I have seen was a bunch of cars towed, but I have heard of fiires and control units shorted out and damaged. If I see what your pictures show I quit doing diagnostics on the vehicle till the harness is repaired. We always do a hands free observation before major surgery as just touching that harness will creat issues the become "since you worked on it" problems.

I wouldn't consider using a car with such an issue. It doesn't go away.

nissanzx1 · #3 09-28-2008, 11:09 PM

It could easily last another year..... Then again, you could have an engine fire tomorrow. Considering what your car cost new, $650 is a drop in the bucket. To me, it'd be worth spending the money not to worry about it anymore...

I used my economic stimulus money on my harness earlier this year

Don't mess around with the mass air flow sensor or anything else until the harness is replaced.

-GH

deanyel · #4 09-28-2008, 11:35 PM

I personally wouldn't do anything until it showed some signs of a problem. The great advantage of the 119 wiring harness problem is that you don't have to touch it - either to do a head gasket or to change the plugs. I can understand why a shop wouldn't want to go near it but the likelyhood of it going from good running condition to fire without any operating warning signs is pretty slim. The problem with getting ahead of the curve with preventative work on these cars is that their eroded market values leaves very susceptible to being totaled at any time from a relatively minor fender bender. But it is only about $500 if you shop around and a couple of DIY hours to install - personal choice.

Larry Delor · #5 09-28-2008, 11:36 PM

If the Ignition module gets fried, you will find out that the harness is cheap in comparison.

Pete Geither · #6 09-29-2008, 05:51 AM

Change it and change it now !!

hodag · #7 09-29-2008, 12:21 PM

Yeah, I vote for the "fix it now" crowd. Only bad things happen to those who put off necessary maintenance, and this is obviously very necessary.

amg280 · #8 09-29-2008, 01:40 PM

I have been driving my 400E for the last 4 yrs and 98000 miles on a harness in much worser shape than yours. To me, the car isnt worth putting a harness in it. That would be almost 50% the cars value (for mine, anyways).

It still bugs me Benz turned there head on this obviously widespread problem...shame on them.

#9 09-29-2008, 08:04 PM

These cars are cheaper to operate than a brand new car but they are not free to operate! That harness needs to be replaced pronto.

Consider yourself lucky that the M119 harness is considerably less expensive than the M104 harness.

deanyel · #10 09-29-2008, 08:28 PM

Very mysterious - all these opinions that it must be done now. What could be the logic for this? It doesn't have to be done now. You can do it now - or not. It's a 119 motor - it could go for years, indeed until the very day it arrives at the salvage yard, without even the hint of an operational problem. If and when it does act up you need to be prepared to act.

#11 09-29-2008, 08:32 PM

My comment was based on his complaint re: the idle. Probably a reasonable assumption that is an early indicator that the harness needs to be replaced, but then again he could get lucky and the poor idle could be caused by something else...

Larry Delor · #12 09-29-2008, 09:11 PM

Quote:

Originally Posted by Larry Delor

If the Ignition module gets fried, you will find out that the harness is cheap in comparison.

The reason I mentioned the module specifially was not a coincidence. My module was fried, and its demise was blamed on the harness. This was about 4 years ago (around 80k miles on the odo at that time). The module was over $2100.00

For that kind of money, I will sell you my 94 E420 - and it comes with a not only a replaced harness, but a new air mass meter as well (also not cheap), and 4 brand new tires.

wbain5280 · #13 09-30-2008, 01:28 AM

If you are handy with a soldering iron and other tools, you can rewire it yourself. This is detailed by a V12 owner.

http://v12uberalles.com/articles_and_info.projects_page.htm

http://v12uberalles.com/MAF_rewire.htm

http://v12uberalles.com/throttle_actuator_rewire.htm

Or you can get a replacement harness.

http://www.peachparts.com/Wikka/M104WireHarness

Pete Geither · #14 09-30-2008, 06:50 AM

Quote:

Originally Posted by deanyel

Very mysterious - all these opinions that it must be done now. What could be the logic for this? It doesn't have to be done now. You can do it now - or not. It's a 119 motor - it could go for years, indeed until the very day it arrives at the salvage yard, without even the hint of an operational problem. If and when it does act up you need to be prepared to act.

Logic might be like mine when my wife was left stranded in a not very nice place, at night. It can happen. I had no idea the harness was as bad as it was, and the price of the harness and the 20 minutes it took me to install it was much cheaper than a new car.

Tomguy · #15 09-30-2008, 09:51 AM

To the people who say don't replace it: Have you ever seen an engine fire firsthand? Or have you ever shorted the (+) terminal of your battery on the frame with a screwdriver and see it melt? I've seen both firsthand (not my doing on the latter, I know better; my friend did not). I would replace it. Right now you may have a $3000 car, would you rather have a $300 pile of scrap metal?