W124 280 Wiring loom

[HRChui]

Hi all,

I am new to this forum and I understand the wiring loom issue has been addressed before, but I cannot find any answers to my perplexing situation.

I have a 94 E280 Estate that went in for other repairs almost a month ago when they discovered the degrading wiring loom. I knew this was a common issue and that Mercedes supply new looms, so we ordered a new wiring loom from Sandown Mercedes and it was fitted promptly. They told us they had already sold 14 this year! However, it was discovered that the wiring loom supplied had 3 extra connector plugs that sit near the cam cover and VVT area. We contacted Mercedes, who said that the wiring loom supplied is the only part they have for our engine and that they are unsure why there are 3 extra connectors attached, and whether they affected the operation of the engine. They told us they would have to contact Mercedes UK and Technical to enquire about this and they only came back to us a couple of days ago saying that they did not know the answer and that they would have to contact Mercedes Germany, which would take 2+ weeks to get a response due to Covid-19! I do really need to get the car back soon and I am hopeful there must be someone out there other than Mercedes who has any information about this.

Thanks in advance.

 

[SL300-24]

Did you check it against the other loom or have you fitted the new one and have these left without somewhere to plug into?n

 

[HRChui]

Did you check it against the other loom or have you fitted the new one and have these left without somewhere to plug into?n

Hi,

It was fitted and those 3 connectors had nowhere to be plugged into. Apart from that, it is the same as the old loom. The old loom has part number 1244407832, whereas the new loom supplied by Mercedes has part number 1244405332. Really surprised that Mercedes don't know what they are for and whether it'll affect the firing order etc.

Thanks

 

[SL300-24]

Are you sure it doesn’t go here?

Passenger side on UK cars front wing under the plastic cover

 

[GP801]

Could they be for options that yours does not have? For example not all have cruise control. As these cars get older/rarer MB tend to consolidate some parts to include all possible options into one item. When we got a new wood trim for the centre console it had the holes for all possible switches/options because they now only supply one generic template

 

[HRChui]

Could they be for options that yours does not have? For example not all have cruise control. As these cars get older/rarer MB tend to consolidate some parts to include all possible options into one item. When we got a new wood trim for the centre console it had the holes for all possible switches/options because they now only supply one generic template

The car doesn't have cruise control, so that may be a possibility

 

[HRChui]

Are you sure it doesn’t go here?

Passenger side on UK cars front wing under the plastic cover

Can I ask what that is? Thanks

 

[SL300-24]

Can I ask what that is? Thanks

I don't know but have just replaced mine on my E320. The only cable with a loop connected for a bolt to screw into went there.

 

[HRChui]

I don't know but have just replaced mine on my E320. The only cable with a loop connected for a bolt to screw into went there.

Thanks, I will have a look. I'm guessing that your replacement went well and that there has been no difference in the running of the engine?

 

[SL300-24]

Thanks, I will have a look. I'm guessing that your replacement went well and that there has been no difference in the running of the engine?

The engine is running really nice thanks it ran okay before, however it was merely a matter of time because the wiring was degrading very badly

 

[grober]

As already suggested its likely to be a "one size fits all" thing. These connectors are destined for a unit your car doesn't have - Air Con is only one possibility that comes to mind? - nothing to worry about but I would make sure they are sealed from water ingress in case some of the connections remain live

http://www.autolib.diakom.ru/CAR/Mercedes-Benz/1995/E320/SYSTEM%20WIRING%20DIAGRAMS/5408.pdf

 

[HRChui]

Are you sure it doesn’t go here?

Passenger side on UK cars front wing under the plastic cover

Just been told that when the new wiring loom is fitted, the extra connectors sit at the front of the engine in the middle, close to the cam. Thus the extra connectors cannot reach the area depicted. Incredibly stumped!

 

[carat 3.6]

Just been told that when the new wiring loom is fitted, the extra connectors sit at the front of the engine in the middle, close to the cam. Thus the extra connectors cannot reach the area depicted. Incredibly stumped!

Those connectors are for the secondary air system, most uk cars don't have it fitted so they are not used. The ring terminal goes to the engine lifting bracket, and the other 2 can just be zip-tied with it.

 

[wrdcc01]

Has the air injection pump been reconnected (above alternator), the changeover vale and cam adjuster as that cable looks about the right length and needs the earth loop to screw into the front of the timing cover? If it isn't the air pump etc just tie them up and see if everything works and forget about it.