95 e320 wiring harness conundrum
 

Help! I have a 95 e320 sedan and was advised by my mechanic that I needed a new wiring harness, which I understand is not uncommon. I bought the part from *************** and they have been very professional, asking for the last of the VIN no. to confirm a match, (which is C195716), and they sent me the part, the part number is 1244405632. My mechanic indicates it is not the right part, that it lacks two of the leads. From all indications that is the right part number, which leaves me clueless about what to do. Can anyone confirm that it is the right part number for my car? If it is, I can only conclude 2 possibilities: the part I have was mislabeled by Mercedes, or my mechanic is just plain wrong. As he charged me for a couple of hours to put it on and take it back off, I am in a rather sour spot. Many thanks for any thoughts or suggestions....

You tried to save money by purchasing the part yourself. If you had let him buy the part and make a little money on markup, then he would be obliged to only charge you once for labor.

Now you may have to pay him for double labor since it's not his fault.

Steve

Call Tim in Mercedes parts in the link below. Give him your vin number and he will be able to give you the correct part number. Sometimes it's a good idea to get a part like that at the dealer since if they give you the wrong part they will return it with no problems, so long as when you ordered it you also gave them your vin. Also the chances of getting the right part the first go round are improved, at least at Duval Motorcars.

http://www.trademotion.com/partlocator/index.cfm?siteid=213951&catalogid=0

There is an early and a late harness, they are not interchangeable, and apparently it is not a clean VIN split. But you are sitting on the answer - if the old harness has come out just check the part number. Any MB parts counter will be able to give the updated number - which should vary only in the last two digits.

to softconsult steve: your post is of absolutely no help. nobody posts here to get spanked by you or taught a lesson. you have nothing helpful to offer!

to Ron:I went to my local benz dealer for the harness. the vin was of no help. they would only go by the part number off the old harness. however, you are correct that if they give you a wrong harness they will swap it for the correct one without further charge.

to deanyel: the part number off the old part is good...if you can get it. my old harness had the part number printed on a white shiny plastic tape strip wrapped around the lead wire. it was dirty so I tried to clean it, the numbers got totally smudged and wiped off. there is no other visible place on the harness showing the part number. it may be located in alternate places but you can't see that without removing the harness. not a good idea since replacing the harness is must easier if you lay the new one over the old one are swap plug by plug. pulling out the entire old harness leaves you with 24 or 26 plugs to guess at where they go.

If you got the wrong harness (you are stuck with it) there is only one other alternative harness that could work. by elimination they should know what the correct one is. talk to them, they should work with you. another sure way to check is meticulously trace the existing harness in your car and count how many plugs come off it. the count should either be 24 or 26. that count will definitely tell them which harness you have. as for your mechanic, it should take about 1 to 1.5 hours to swap harness. at worst it will cost you a couple hours of his labor. you don't mention why your mechanic said the wiring harness had to be changed. was there a check engine light that came on or is your mechanic noticing crumbling wire insulation.

I'm guessing Tan Man and EHM are the same poster.

Relax.

My post was not ever intended to help you. It was a comment to others using your situation as an example. I believe there are situations where it is smart to pay a shop to handle the whole repair, part + labor.

I am not alone in this opinion. Finally, I can't recall any MB shops I have used that would allow me to provide the parts. A large part of their gross margin depends on parts markup. Why would they do that?

Steve

Sorry, Tan Man and EHM are not the same. Should have been obvious.

No caps at the beginning of sentences makes reading very difficult.

Perhaps something to think about.

Steve

Thanks to all for the responses; this is my first post on here and I do appreciate the help.

Steve: I do not disagree (now) about getting the part from the mechanic; I wouldn't be in this position had I done that. I was just so sticker-shocked that a daggone wiring harness was almost $1100 that I was determined to save a little; it backfired.

Tan Man: You mention the 24 and 26 wire harnesses; the mechanic said he took the old harness off, wire by wire, replaced it with the wires of the new harness, and came up 2 wires short. It would seem very likely that I got the 24 wire harness and needed the 26? I will try to sort through that with the supplier. Also, you asked why it was being replaced. It was crumbling in places and I was getting occasional bad misfires that we could not attribute to anything else.

I think all of us with cars in the year range for the wiring harness issue, live in fear. $1,100 , Yikes! My '92 300E so far is Ok. Knock on wood.

I just got a '97 S320. Based on this list, I think I am just beyond the point that MB changed to proper wiring, but I am not totally certain. The new indy that I have visited, but not yet used, told me a story of a customer with the identical car having the harness problem and frying several computers. Big bucks, but customer had the car repaired.

I hope you get it resolved correctly. Pretty astounding that MB refuses to acknowledge this obvious defect. Also makes you wonder how it can take
from what '92 to '97 to move away from the dis-integrating type of wire.

I can also attest to the variability of Dealer Parts Counter knowledge. I don't buy there often, but sometimes am faced with the blank stare thing. The doesn't know and doesn't know how to find the correct answer.

Steve

You know these wiring harnesses are simply wire looms with connectors.

Is your guy saying that it is missing two connectors? Seems like he should have taken the old one out and then compared the new one to the old one, counting connectors, before spending the time to put the new one in.

This would be a good I idea for the next new harness.

Steve

Steve,
I like all your observations. You are a very asstute individual, and someone I would enjoy having as a client. You look at things from all perspectives. As you stated I never let a client bring in parts for 3 reasons. First as you say repair facility labor rates are based on expected parts profit or the rates would be higher. Secondly is the situation here. Who pays for second time. Thirdly if the owner supplies the wrong part, you're hoist is tied up for three days til he can get the right part after work one evening. If I get the wrong part, I can have another delivered in a matter of hours.

I like your observation about matching parts. A good professional mechanic matches parts before starting work and never throws old parts away until the job is completed. You never know if you will need a clip or something off the old part or need to look at wear marks or something.

I agree.
Anyone who does these harnesses on a reg basis knows that there was a mid-year change on the ECT sensors and the looms are different . They would also know that ASR looms are different.
That is why the part# from the original is always checked before hand.

Thanks AutoZen.

I sometimes get some flak for the sort of contrarian nature of my comments.
People often react from a very narrow point of view. This thread is a good example.

The guy who came back with comments to previous posters is only thinking about the specific problem. I tend to view threads as topics for discussion.
One of the reasons, in my case, is that I am not a professional mechanic. I can only offer up my view of how to approach the problem in general. I really value and enjoy the responses from people in the business who actually see these problems in real life.

I do problem solving for a living. Consulting with clients in my industry about how to run improve operational efficiency. Of course, when the inter-action is live two way communication it's easier to help them through problem identification and suggest solutions. These forums are largely one way with long delays. They are also, by definition, have members from a wide variety of backgrounds, educational levels, and occupations. That makes for some contention, frustration, and hopefully some reflection.

Steve

Ehm, I too was initially sent the wrong part number (124 440 56 32) by Phil when I replaced my engine wiring harness. The correct number for my car is (124 440 29 33), which is more expensive. My VIN ends in C230097. Phil made the comment that mine was a late 95 production model. Double check by looking for the original part number on a tag located roughly 1-2 feet from the bulkhead connector.

parts-customer supplied or not
 

steve,autozen, agree with you both completely.when a customer comes in the door part in hand and asks to have it fitted to all intents and purposes he has made his own diagnosis which if it doesn't work guess who gets the blame?i usually ask those people how they fared when they carried their own steak into a restaurant and requested cooking service.

I differ with your opinions. It's true you don't see someone bringing thier own steak to a restaurant...but its common to bring your own bottle of wine. Some restaurants charge a corking fee for using the corkscrew tool. they are happy to have you for all the other profit you generate when you buy coffee and desert after the steak.

As for softconsult, you made your position clear in your post early on in this thread which stated:

"My post was not ever intended to help you".

I'm sure that's the attitude ehm was looking for on this forum in his first post.

Is that called....professional problem solving?

Yes, you can bring your own bottle of wine, but as you pointed out, you pay a fee and pay for the rest of the service. If you don't like the wine, you just have to drink it. The restaurant will not let you tie up the table while someone in your party goes for more. That would be like tying up the hoist waiting for the correct parts. You also mentioned buying coffe and dessert. Does that mean that when someone supplies their own parts I should offset that by finding more work the car needs while its there? Actually that won't work, because the guy will want to set up another appointment so he can get the parts.

Funny you should mention that owner diagnosis thing. Years ago I had a guy come and make an appointment to replace his water pump. He didn't want me to check the cooling system. When the car came in, there was a definite leak in the water pump area. As I started work on the car, I couldn't help wondering why he wanted his water pump changed Oh well, it was his call so I did what he asked and changed the pump. I didn't even charge him any extra for tightening the hose clamp that was leaking near the pump.:D

Well Tan Man, you somehow fail to understand that my original post, the one you find so offensive. I was simply to make the point that for certain repairs it's better to let a pro buy the parts and do the repair.

My additional point was to point out that shops depend on parts markup for a significant part of their Gross Margin. You want to argue with the restaurant analogy by bringing up BYOB and corkage. Why argue this point? Shops set their own rules. The advice, I know you hate advice, would logically be to ask your shop what their policy is , before you run out and buy parts.

You think it's my posts are not helpful because they don't provide a specific answer, or even a guess. You think these suggestions should not be made.

Apparently, you are in the minority on this one. Several people, a majority by count, are in agreement with me. Actually, the original poster said he is now in agreement.

So you have your opinion and I have mine. I will continue to offer my thoughts, and so will you. No problemo.

Steve

Actually I forgot to address Tan Man's sarcastic line, "This is professional problem solving!"

Actually, yes it is. It's just that your perception of the problem and my perception of the problem are different. Problems are usually things that continue to occur. You are immediately going to react, and think that the original post was a specific problem to be solved. It was, but it more than that.

Open your mind just a little. Realize that some other person in the future may search the forum for "Wiring Harness" and find this thread. Don't you see that some advice that goes beyond the specific problem might be helpful?

Solving the problem is not just correcting the specific occurence. It is figuring out how to prevent it, and similar ones in the future.

So here we have the specific occurence, wrong part. It has already happened. Question is how do we prevent it from happening again.
I offered up one way. Others, including you, offered up some other suggestions.

By the way, it's not unusual for people to not understand problem solving.
Most managers I deal with are absolutely terrible at it.

Steve

1992 Mercedes do NOT have wire harness issues...only starting 93-96(very few 97), model had the biodegradable material .

Seems to me that a sometimes DIYer really needs to have a shop that will let them bring in the parts now and then. Sometimes you don't make a decision on whether to do it yourself until you see the part and figure out how it all works. In my experience a lot of good honest shops will let a good customer bring in their own parts. That's my first question for a shop and won't use a shop that prohibits it. I think a good honest shop doesn't have a parts profit margin that is so great that they have to be all that concerned about it. Of all the functions that middlemen typically provide to earn a profit margin an auto repair shop is performing very little of them. If their profits margins are that exciting to them I'm a little suspicious.

True on the 300E in question but 92 400E wiring harnesses are not so great, probably not as bad as 93+ 104 HFMs.

Try telling that to people who own 1992 400E and 500E's.

Anyone who has read the"codes" and associated thraeads is aware of the infamous "main" harness and its association with control module and actuator. When I replaced the oil sensor (in oil pan), I realized another harness had the same detoriating insulation. I replaced the 3 wires for the "B" harness.

However,

Arthur Dalton's comment in this thread...
<Anyone who does these harnesses on a reg basis knows that there was a mid-year change on the ECT sensors and the looms are different . They would also know that ASR looms are different.>

presents the question...
Are there other harnessessss (with the ng insulation), that could cause these codes and cause one to falsely suspect control module and/or actuator?

Bob
PS Last night, wife came home in "Limp Mode" in our 94 e320. Pin 8 Code 8 & Pin 14 Code 3. OVP relay new #, New Stop Light Sensor, Wire harness replaced by PO, 4Mercedes rebuilt actuator and control module tested OK. I want to give 4Mercedes the benefit of doubt that their work is OK and someting else is causing the codes & "Limp Mode."

<<presents the question...
Are there other harnessessss (with the ng insulation), that could cause these codes and cause one to falsely suspect control module and/or actuator?
>>

sure is .. the pigtail harness to the EA is not part of the wire harness and is another common insulation bio-degrade problem.

owners with their own parts
 

i open my shop on saturday mornings for two reasons. 1 so that people who cannot get here during the week can pickup and drop off their cars. 2 so that good customers who want to diy can bring in their parts,have access to tools and have access to help when they run into trouble.

David, that is a great business approach. I'll bet the word of mouth advertising keeps you predictably busy.

Denayel, you wrote, "

In my experience a lot of good honest shops will let a good customer bring in their own parts. That's my first question for a shop and won't use a shop that prohibits it. I think a good honest shop doesn't have a parts profit margin that is so great that they have to be all that concerned about it."

A couple of comments.

That's a fine strategy, if and only if, you are in area large enough to have more than just a couple of MB shops. My area has 3 that I know of and none will allow customer parts purchase. I have a general shop about 3 blocks away from me. He will work on MB and actually welcomes me bringing parts to him. He would rather not hassle with sourcing parts that are not routine for his shop. However, I tell him to just add something somewhere to make up for his lost margin. Whether he does or not, I don't know.

I don't know if you have ever been self-employed or owned a business. My guess is not. I really don't understand how you can connect honesty with concern parts profit. You mean the only shop owners that worry about parts margins are dis-honest? I don't own a shop, but I understand it's quite a tough business.

Maybe a couple of shop owners will post a reaction. My bet is there are so few people actually wanting to bring in their own parts, that those shops allowing it are just winking because it's not significant. The shops that prohibit have made the business decision that it's just not worth the delay and risk involved.

Steve

I'm not trying to hijack this thread. Really.



David, I admire your dedication to your "good customers". Every DIY'er I've ever met would give their right arm for access to a lift and air tools, not to mention professional advice!!! I'm curious though. Do you charge a fee for the use of your shop and equipment? How do you decide who's allowed to work in your shop and who's not? Do you put limitations on the type of work you allow them to perform? Have you ever lost a customer because you turned down a request to use your shop?

Didn't say it, didn't imply it. I hold no grudge against a shop that doesn't allow customers parts - entirely their call, it's just not what I want in a shop. I've been self employed for last 12 years.

The Latest...
 

OK, I've had a development since my original post. I found the part no. on my original part and it is 1244402933; the one that was sent to me was 1244405632. So as several of you mentioned, the Mercedes computer is simply wrong as to some of these 95 e320 wiring harnesses - we entered the entire VIN and it came up with the wrong part; so you can avoid a mess such as mine buy (1) letting the installer get the part (so at least if it's wrong its his or her problem), or (2) if you are providing your own part (and there is a healthy discussion above concerning this option) checking the part no. of your original - it does seem very hard to go wrong if you have that part no. first.

So I guess here's my question now: isn't that 2933 a replacement part? I'm now thinking this harness has been replaced (and now questioning my mechanic on the need for a replacement)... I checked a lot of the harness in looking for that part number and the only frayed part I found was one place where it connected on top of the engine (near that plastic shield on the front). I am thinking: return the wrong part, wrap some electrical tape on the frayed area, put my $1000 back in my pocket and drive on? Thoughts... ! (I know it's hard to say without seeing it).

A dealer parts counter can tell you more but that does sound like a replacement part and you should question why you would need a new one. The replacements are supposed to be free of the original problem.

ehm

You wrote <the only "frayed" part I found > My quotes.

A bad harness has dried out brittle insulation of the wires. Frayed black wrap surrounding the wires is not the problem.

Bob

I believe the replacement wiring harness has the prefix S(?) in front of the part number on the tag.

Outcome
 

Thanks to all who posted in response to my initial one; I thought I owed it to all to provide the final outcome: unfortunately the harness on my car had not been replaced; the more I peeled back the black wrap the more crumbling that appeared, so I ordered the new one to match what I finally could confirm was the right number and hopefully now I am in good shape. An education in any event...

Why do mechanics charge an hourly labor rate if they don't want to sell labor? If restaurants charged an hourly cooking fee then I would feel fine about brining in my own steak and asking them to cook it.

Also, why do mechanics feel that they can rip customers on the labor rate AND the part costs? I can't think of any other business that can charge you for 4 hours of labor when it only actually took 2.