'92 V140 600 SEL Harness Help

[drewpasmith]

Hi all,

As spring approaches (yeah right), I'm starting to recommission the beast for the better weather.

Last year, I had wiring to one of the ETAs replaced (there was evidence of insulation failure and a blown EGAS computer to boot) but soon ran in to difficulties with:

1) rough running at idle
2) hunting at idle
3) surging
4) limp home mode kicking in
5) 1 stall
6) ABS/ASR lights always on
7) really rich running

Now, I know I have a faulty ABS sensor at the back which will fire limp home mode.

But for all the other things, I'm suspecting further wiring loom failures.

Before I take her in for a service, can anyone illuminate me as to the following:

1) Which of the engine wiring looms, which seem to be referred to as Upper and Lower, is likely to be the culprit here?

2) What are the part numbers for these looms?

If anyone has any further experience/insight to offer around the issue, I'd also welcome that.

Oh, and if you're interested, here's what we got up to last summer:

x600

Cheers,

Drew

 

[Sp!ke]

Where are you based?

 

[drewpasmith]

I'm based in North London, N4 to be precise.

 

[Sp!ke]

I suggest taking it to someone that knows this particular model well and isn't scared of taking it on.

If you can make it to Brentford, Martin at Finch Motors had one of these himself. He'll enjoy working on it rather than being reluctant to touch it as many will be.

 

[grober]

This is the website you want :- V12 Uber Alles, Repair Help for Mercedes Benz S600 V12 W140

In particular

V12 Uber Alles, Rewiring Electronic Throttle Actuators in a W140 Mercedes Benz

V12 Uber Alles, Rewiring the Mass Air Flow Meter (MAF) Connector and Wire Harness in a Mercedes Benz S600


This is also an excellent site for the W140 COUPE K6JRF Auto Page


you will notice these are all sites derived from the WEB archive so may not be totally complete [ odd missing picture or link that doesn't work]

 

[drewpasmith]

Thanks chaps; both helpful suggestions.

She's currently being looked after by Ivan and Joe at Automerc in Harringey.

Although not 600/M120 owners themselves, they've been fearless in taking on work on mine.

That said, I'm wondering whether a 140/120 specialist might be a better bet...

 

[BlackC55]

We did a massive overhaul on a 120 engine a few years ago. The loom was completely ruined when we too the heads off.

It's documented on here.

 

[drewpasmith]

Hey mate,

Thanks for bumping the SL600 thread for me. What a mammoth job!

Just out of interest, which looms did you replace, and did you use new Merc looms, or did you rewire it yourself?

And, just out of curiosity, why did the engine need a complete rebuild?

Cheers,

Drew

 

[BlackC55]

It was the complete engine loom. Bought from Mercedes.

It was not a complete re-build. It was just head gaskets and various oil seals.

 

[drewpasmith]

BlackC55,

Just out of interest, do you happen to know the parts price of the looms, and the labour cost to change them?

I'm struggling to research these things elsewhere online...

Cheers,

Drew

 

[V12]

I'm pretty sure Colin Ferns had 1 or 2 of these himself, so he'll likely be experienced with working on it.

 

[grober]

Part no I have is A1405404705 much discussed here. Google Translate

price £575.64 FROM Inchcape CABLE HARNESS - E Class 1985 - 1994 E250D - Mercedes-Benz Parts, Inchcape

BUT
there is also a body mounted wiring loom in the engine compartment associated with the air conditioning
A1405405105
Don't confuse the two.

 

[BlackC55]

Can I have the first six of the chassis number WDB****** and I will check the labour time.

 

[drewpasmith]

Can I have the first six of the chassis number WDB****** and I will check the labour time.

Here you go:

WDB1400572A038628

Much appreciated

 

[BlackC55]

The labour time is what is called a "ZM" time. This means its time taken to do the job. I "estimate" it to be about 2-3 hours work.

 

[drewpasmith]

Part no I have is A1405404705 much discussed here. Google Translate

price £575.64 FROM Inchcape CABLE HARNESS - E Class 1985 - 1994 E250D - Mercedes-Benz Parts, Inchcape

BUT
there is also a body mounted wiring loom in the engine compartment associated with the air conditioning
A1405405105
Don't confuse the two.

Fascinating!

I knew the M120 was a bit of a mongrel born of MBs pre-existing 6 cylinder engines.

But a wiring loom from a diesel?

That's a bit of a giggle

 

[drewpasmith]

So. an update:

First of all, Martin at Finch Motors is becoming a minor legend in our household for his patience and diligence. I'll wait until the job's done before giving a full recommendation, but suffice it to say, we're in a good place.

So far:

1) he's replaced the engine wiring loom (OUCH)
2) he's replaced the one MAF loom that hadn't previously been replaced (ouch)
3) he's replaced a duff ABS sensor (eh)

and Diana is now running at 98%.

That final 2%, you ask?

A very slight, very intermittent misfire under low load.

As Martin correctly notes, if you've ever experienced a W140 600 at 100%, settling for 98% will never be enough.

So, no codes are being thrown by her Amstrad-grade computer so we're now settling on the HT leads, which are 56k-mile originals.

Mercedes will happily sell individual components (leads, caps and connectors) for a grand total of £700 for an M120.

This is crap.

Beru and Bosch have both made lead kits for the M120 over the years, but we're having trouble tracking down suppliers.

This is where you, dear MBClub readers, come in.

Do you know where I can buy new Beru or Bosch leads for a '92 W140 600 SEL?

Over to you with thanks in advance.

Drew

 

[E55BOF]

Try this on eBay (I haven't worked out how to post links yet). In the States, $150 or so, postage extra.

92-95 Mercedes 600SEC 600SEL 600SL SL600 Spark Plug Wires FB71634 ZEF634 #SW0892-95 Mercedes 600SEC 600SEL 600SL SL600 Spark Plug Wires FB71634 ZEF634 #SW08

Any good?

E55BOF

 

[V12]

92-95 Mercedes 600SEC 600SEL 600SL SL600 Spark Plug Wires FB71634 ZEF634 #SW08 | eBay

Have you considered getting custom leads made from scratch?

 

[BlackC55]

Before you splash out on leads.

The inlet manifold gaskets are prone to leak on the 120 engine and cause a misfire.