Wiring harnesses insulated with Firebraid

[jstadter]

I've been meaning to post these pics for almost a year, so while I'm sitting here waiting for kids to come around trick-or-treating, I'll finally post them. When my ETA went out last year, I discovered that the lower harness had disintegrated, so I replaced it while I was doing the ETA. My upper harness had already been replaced just before I bought my car, so it was fine. In an attempt to slow down the effects of heat on the harnesses, I covered both the upper and lower in a flexible insulating sleeve called Firebraid. Whenever I could, I slid the sleeve over the harness and secured it at each end. In the case of the upper harness where wires branch off to injectors, etc., I had to slice the sleeve lengthwise and then wrap it around the wires and secure it every few inches with zip ties. I didn't have any clearance problems with the air box when I put everything back together. The Firebraid isn't cheap, but if it makes the harness last a few years longer, I think it will be worthwhile. I paid approximately $150 total for various sizes and lengths from http://www.ioportracing.com.

Jim

[MrMotul]

Nice job Jim, did you have any trouble getting the Insulation on where it gets really tight, like the bit that lay's on top of the cam cover where the harness sits in the grooves provided? when I replaced my harness on my E60, I covered (where I could) with a heat insulating tape similar to what you would put on something extremely close to the Exhaust but it does not look anywhere as nice and smart as the job you have done. I am soon to fit another Harness to my 500E, I still have quite a bit of the insulating tape that I applied to the E60 left, hopefully I can make it look nearly as smart as yours,
Congratulations on a very smart job and thanks for the info,

Regards,

Terry.

[jstadter]

Hi Terry - thanks for the compliments. Regarding the tight areas, the only areas that were somewhat tricky were where the breather tube and wiring harness come off the ETA. There isn't much room inside the intake spider to begin with, and the insulation is somewhat thick (imagine a terry cloth towel with a layer of vinyl over it), so I had to slowly coax those pieces into place, but otherwise everything went pretty smoothly. If you notice in the pic taken from the top, just below the access port of the fuel raid at the front of the engine, there is some Firebraid that disappears into the intake spider. That piece covers the vacuum line that starts at the back of the intake, travels under the spider, behind the power steering reservoir, and over to the left fenderwell into an electro-mechanical black box. From the factory the line is covered in a black corrogated plastic sheathing which crumbles over time. I managed to get a single piece of insualation on that line. That took quite a while due to cramped quarters, but not really because of any clearance issues, and apparently if the line breaks it can cause rough running issues that are very difficult to track down, so I figured it warranted the extra protection.

As for the bit of the harness that sits in a groove in the cam covers, the only area I'm remembering like that at the moment is on the right rear cover where some harness connectors mate. I didn't cover the connectors, so I may have inadvertantly avoided the tight fit you describe.

The lower harness and ETA were such a PITA to replace, that I'm hoping the insulation will postpone me having to do that job again for a few years. I wish MB would have done the honorable thing and just recalled those harnesses.

Jim

[FunfHundertE]

Very nicely done ...I just bought some 'Thermotech' heat barrier fabric and will do something along the lines of what you did this winter.

Too bad MB couldn't come up with something similar from the factory for protecting the wires from heat (after the fact). Guess they want you to buy new harnesses every 5 years or so.

[jstadter]

Jim - I assume the Thermotech fabric comes in sheets like cloth fabric does? The fabric may make it easier for you to work around the thin lines that branch off the upper harness for the fuel injectors. Also, if you use zip ties to secure it, you might do a bit of research to see if there are some that are better suited to high temps. Mine are just generic zip ties, and I haven't had any problem with them so far, but high temp versions would make sense in this application.

Jim

[FunfHundertE]

Hi Jim

Yes, Thermotech you can get in sheets but I bought the pre-made loom ones and have just taken the stitching out so I can wrap them better/custom and also since they won't fit over many of the connector ends. The product isn't as stout looking and yours but is also much cheaper (in price hopefully only)

I was thinking of using safety wire instead of zip ties...but I think zip ties would be fine even with the heat...and easier to do.

Your avatar is too cool...I have not found that magazine with that picture...what is it from? I would love to show the 928 guys around here that one.

[M104-AMG]

Wasn't that avatar in a MBCA Star or Mercedes Enthusiast periodical ?

BTW: there are stainless-steel zip-ties available . . .

:-) neil

[infoage1]

Kinda hate to be a wet blanket here, but I am in contact with a woman who is getting every wire in her 95 SL500 replaced because of decomposition. Bumper to bumper. Low miles. She is the original owner. I think she said $12,000 was the quote.

Here's her miss-catagorized NHTSA complaint:

NHTSA Complaint Summary

Make:	MERCEDES BENZ
Model:	S CLASS
Year:	1995
Complaint Number:	10159899
Summary:
PARTS OF THE ELECTRICAL SYSTEM BEGAN FAILING. DRIVERS WINDOW WOULD NOT OPERATE AND AFTER MUCH TROUBLESHOOTING BY THE REPAIR SHOP, THE SWITCH WAS REPLACED. SEVERAL WEEKS LATER GAUGES ON THE DASH FAILED AND THE PASSENGER WINDOW AND HORN FAILED TO OPERATE. AFTER DISASSEMBLING THE INTERIOR (SEATS, CONSOLE, DASH, ETC.) THE REPAIR SHOP CAME UPON THE PROBLEM - WIRES SHORTING ALL ALONG THE WIRING HARNESS AND CAUSE SPARKS AND SHORTS THROUGHOUT. *NM http://users.adelphia.net/~infoage1/complaints_nhtsa_mercedes_wiring_harness_failures_ 1991_1996.html

[jstadter]

Jim and Neil - I'm not sure about the source of the 928/500E pic in my avatar. It was obviously a full spread scan because the crease shows in the larger version. It was posted on the Rennlist 928 list years ago and I saved a copy. I have the larger jpg if someone would like a copy. Thanks Neil for the heads up about the stainless zip ties. I wasn't aware of them.

Tom - I'd gladly give up the money and effort I put into the Firebraid if MB would give me new harnesses for free. Maybe we'll get lucky and this incident will provide ammunition to have NHTSA get on MB to fix the issues - but I won't hold my breath.

Jim

[cm60k]

i can"t find the (E60 AMG) piston number,,,,! it is the same of (500E 6.0) & did i must to fixing an original one,,,?? any help.........thanksssssssssss,,,,,,,

[run.exe]

i can"t find the (E60 AMG) piston number,,,,! it is the same of (500E 6.0) & did i must to fixing an original one,,,?? any help.........thanksssssssssss,,,,,,,

You may wish to delete your previous question and post it in the M119 forum, as this thread deals with wiring harness issues...

Kind regards,

[Paul64]

I bit the bullet last night and ordered up a new harness - 124 440 2006 - for the grand sum of €540.
Bit of a stinger eh? It seems to be getting dearer every month....
Also going for a new fuel pressure regulator and throttle idle speed contact switch.

Any tips for getting the injector connectors off? I had a quick try last weekend and it seems to be pretty difficult to prise them away and I don't want to damage the injector fitting.

Has anyone cleaned the injectors at the same time as changing the harness? It would be a good time to do it but, as I have only done 70k miles, I wonder if it might be necessary yet?