View Full Version : Deteriorating wires to starter

11-10-2012, 02:03 PM
Upper wiring harness has been replaced, but I noticed the insulation to the wires going to the starter have cracked and broken down.
What is this part number? I think I need to replace it before it leaves me stranded.

11-10-2012, 02:15 PM
Here you go: Courtesy of Wiki page

Part number 124-540-27-30, list price $312 USD (MBNA MSRP, Mar-2012)
Note:Fits 124.036 chassis ONLY! The 124.034 uses a different part number with different connectors.



11-10-2012, 02:31 PM
This is a very good thread on replacing the lower wiring harness.

You will need two 12" extensions and a 10 mm deep socket to get to the nut that holds the harness right where it goes up through the body. I think the hardest part of this job was trying to deal with the small nuts on the alternator, starter and the 10 mm harness mount nut. I also used a ratcheting angled screwdriver wrench from Sears to get to the small screw on the starter. It will probably take you about two hours to replace it.

11-10-2012, 03:49 PM
Thanks. There has not been any issues with the wires, but they are degrading. I'll try to do this when I get a lift and time.

11-10-2012, 08:28 PM
Parts.com had mine for ~$230 if I remember correctly (which I do) about a year ago. I replaced my starter at the same time since I was in there. My harness was completely degraded. All the wires were bare and touching each other. I ha a sporadic issue with my battery not charging and leaving my stranded/ after replacing the harness, the problem has not resurfaced.

Good luck!

11-12-2012, 04:19 PM
Trae, don't know if you have seen it posted but here's one for sale from a former owner : http://www.500eboard.com/forums/showthread.php?3466-Sold-My-Car-Selling-All-My-New-and-Used-Spares!

11-12-2012, 04:22 PM
That's a good price from Gregg at $200 shipped... it will be ~$240 from parts.com with shipping.


11-12-2012, 05:08 PM
Yes, it's brand new in Mercedes box straight from dealer! Bought it "just in case" and never needed it.



11-12-2012, 06:21 PM
Gregg, I think that I, too, would be buying it "just in case." I can see spots where the insulation is breaking, but no bare wires yet

11-12-2012, 06:33 PM
Not trying to be pushy but you might want to pull the trigger; I've gotten a couple of PMs about the harness. I suspect it will be gone soon.....


11-12-2012, 10:42 PM
Trae, I also would suggest replacing it ASAP. With the alternator pumping current through that old wiring, it really is a fire hazard. I was very surprised I hadn't ignited after seeing the state of mine. It was only so bad at the connections, but the worst parts were in the middle of the harness where it actually flexes with engine movement. The ends are probably the least destroyed as they don't move much, y'know?

11-13-2012, 06:01 AM
O.K., I am convinced. I'll buy it.

11-13-2012, 01:52 PM
I was too late, harness already sold!:runexe:

01-29-2013, 06:23 PM
Replaced lower wiring harness today with my local indy. Now my car should not burn up because of exposed wiring. Boy, was the wiring BAD! Glad you guys encouraged me to do this job.

01-29-2013, 06:45 PM
I wouldn't be surprised to see the small wires shot, but how about the large wires to the starter and alternator?

01-30-2013, 03:21 AM
The large wires were OK. The small wires were terrible, ie. . . flaking insulation and bare, exposed wire.

01-30-2013, 08:22 AM
The larger wire uses different insulation, sort of a cloth material. The smaller wires use a plastic-y insulation that falls apart. The replacement harnesses have improved insulation that lasts much, much longer. You will probably never need to replace it again.