Problem Description and Possible Solution
The engine wiring can degrade because the insulating material falls off leaving the bare wire exposed. This can cause many problems depending on which wires are exposed and what they touch.
Problem DataRepairPal Verified
Average mileage: 109,292 (23,800–200,000)
17 people reported this problem
Biodegradable insulation visibly cracking and falling apart where wires were visible at plugs attaching to sensor on thermostat housing at the front of the engine. Found a 2007 with the non-biodegradable insulation at a junkyard and replaced the original, starting with the big computer plug behind the battery and just worked around to the front of the engine replacing each connection with the new harness equivalent one at a time. Under three hours.
Engine harness wiring insulation failure
Problem is as described in heading. Dealership basically said to throw the car away or spend the money to have them replace the harness. MBUSA denies anything is wrong.
most of the wiring harnesses are exposed, and most of the sensors have poor connections due to lack of insulated wires. they are cracked and extremely poor. occasionally when i enter certain turns usually sharp right freeway on ramps i believed caused the wires to touch causing my vehicle to lose power and almost cut out, but it recovers on its own and proceeds onto the freeway but in heavy traffic areas almost caused other cars to rear end me and or have to swerve to avoid me, which is dangerous. there is usually no warning from the car, it just happens out of no where when least expected. weather/temperature may also contribute to this matter, but could happen any time and usually on the same highways and or turns, on ramps ect.
i read that mercedes used biodegradable coating on all their wiring without takin into consideration the climate changes and the heat radiated from the engine. some of the wires i have recoated with electrical wire but some wires are difficult to reach making it difficult to insure the wires do not touch.. Some day i plan to purchase new ones but i am unemployed which makes repairs difficult to keep up. as for now the car is not working and parked in the driveway.
The biodegradable insulation that Mercedes chose to use does actually degrade by design. Unfortunately, I'm not done using the car yet. There are areas around the headlamps and side marker lights that the wire insulation does literally crumble off into your hands.
I paid $i,800. for my mercedez e-320.Only to find out a wiring harness problem with the insulation on the wire.
My question is why isn't there a recall on this problem?
Dos'nt make any sense to me why Mercedes benz dosen't stand up to the plate and replace this safety hazard.
To replace the part is rediculouse in price and labor.
If you can find the part for resonable price i will be glad to pay you for it...
I just took my car in for what I thought was a spark plug n wire issue turns out the engine wire harness is literally crumbling apart. My mechanic told me he highly suggest not to drive the car at all and pretty much I've been without a vehicle for almost a month while I save up the 800-1000$ it's gonna cost to replace it. This is the third one my mechanic told me he has replaced on this year vehicle .
Car surges to high ram immediately on start up.
Replaced the wiring harness to the mass air flow sensor and the fuel injectors.
Cracked wire harness insulation was starting to cause problems with engine diagnostics.
The problem started at 80K miles, I had Mercedes replace a single wire at the time and complained.
They blamed me for having the car overheat and did not tell me the factory used the wrong insulator on the harness. Shame, the car never overheated.
I eventually had it replaced at my Mercedes mechanic for ~$1200 at 110K miles.
To replace the wiring harness, it took me about 2 1/2 hrs. Some of the connectors are hard to access and you have to move a couple of component parts to get too them.
If you are not auato repair savvy, have it done.
Insulation on eng. wiring harness cracked causing no ignition voltage and shorts. If not rpaired, in can cause ECM failure.
Fix. Replace entire eng. wiring harness, $700.00
The engine wiring harness on my 1995 E320 Cabriolet (124 chassis)shorted. I've already replaced the high voltage pro-tection relay. I've ordered a new OEM harness ($945). How many hours should it take to remove the old harness and install the new one??? What can you tell me about TJ's Bobby and Steve's Auto World in Bryn Mawr, MN?? How about Huber's Imported Auto Repair??