500E Availability of upper engine harness '94 E500?

[mpmorris]

This past month and after a vigorous 4-day road rally (on and off-road twisties), I now have a delayed cold start, the fuel pump relay sounds like a purge valve at idle and the engine idle periodically is 'lumpy'. A look at the harness shows serious deterioration so that is the first order of business -maybe it will solve my ASR illumination after warm-up that I've had during my ownership.

I've gone thru the posts on this forum but have not found a source for replacement of the upper harness nor a source to properly rebuild my existing harness. Any suggestions?

Thank you for input

-Michael Morris

 

[doolar]

Just order a new harness, no need to rebuild it yourself. If you put in ”harness” in the search box and tick the box for only searching thread titles you’ll find info on part numbers etc. Very easy to replace yourself too.

 

[mpmorris]

Thank you, Thomas -just tried again but no success.

 

[gsxr]

The 1993-1994 USA model year engine harness 124-440-20-06 was $640 MSRP, but apparently is NLA now. Try calling a dealership to check worldwide inventory, in case there are still 1 or 2 floating around on a shelf somewhere.

That said, the 1992 harness p/n 124-543-95-26 is functionally equivalent, and still available new. $570 MSRP, discount dealers have it for $390-$400. I would try that first.

The fuel pump relay clicking is caused by failed capacitors in your LH module. A new harness WILL NOT fix that clicking. Send your LH module to @Alphasud40 for repair (click here).

It's unlikely the new harness will cure your ASR light / limp mode after warmup. You'll need to clear all fault codes, then see which codes return after the next time the ASR light turns on. That will help identify the culprit. Most common causes are failing ETA internals, or a faulty NSS (which is NLA now).

 

[mpmorris]

Thank you @gsxr for the part numbers and contact for the LH. I'll call the classic center to run down a '94 harness otherwise order a '92. Dollar-wise I have a wholesale account with MB. The ASR illumination will come on after about 5-10 minutes of run time -car does not have to move -but the ASR switch does engage if the light has not yet come on and the car is in motion. Have never checked fault codes as it does not affect daily driving (and not on my priority list) -no limp-home issues. Now that I definitely need a harness, I will chase down the ASR & relay issue. Best, Michael.