Engine wiring loom W124 230TE

[The Crooner]

I have managed to source very cheaply a complete wiring loom from a low mileage engine, for my car. The one in the car has a few broken connectors and looks, and probably is, a bit beyond its sell by date.

Are there any pointers I should know before I set about pulling the old one out and replacing it?

I may rebuild the old one with modern automotive wiring, and a few new connectors at a later date.

TIA

Tony

 

[television]

This is worth reading
http://www.mercedesshop.com/Wikka/M104WireHarness


With heat shrink sleeving etc a good job can be made by making you own, and doing it in situ

 

[The Crooner]

Bookmarked ready for action.

Thanks

 

[television]

Just a few tips on doing this.

You want to join a new wire onto a connector, cut the old wire off about 1" from the plug, to strip the plastic off use a cheap cigarette lighter and melt the plastic and the old insulation will come off like butter, this saves all of the pulling with risk to damaging the connector.

Bare back the insulation of the new wire to be joined about ½"and twist the two wires to be joined together, when all is nice and flat then solder up ( do remember that there is no strength in solder, it just hold the strands together, and a joint is only good when its bright and shiny) then slid some heat shrink over each join with a piece long enough go go right into the plug / connector and heat it with a warm air gun, next slide a larger piece of heat shrink over all of the wires on that plug and shrink that.

You must remember to slide the heat shrink on before you join up in many cases, thats the one or two pieces as needed, the ends need to be well back when you solder up or the heat shrink will shrink under the heat of the soldering iron and you will not be able to slide it along.

Picture 1 shows the new wires soldered on, 2nd the heat shrink and shrunk, the third is only for illustration as I am out of stock of a larger size heat shrink, but do slide the piece right up to the connector as it gives support to all of the wires.

The last picture show joining a multi wire.

 

[The Crooner]

I did it today.

I thought it was going to be easy...

I'm filthy, my hands are torn to shreds, I have 7 wires twisted and taped ready for soldering.

But, it started first time, and the idle is solid at 750 from cold with no hunting.

I have various connectors from the old loom, should anyone like to make a donation to a charity of their choice for them.

I'll post them FOC.

Tony

 

[Smudge]

Just an observation,but how do you get on in the future with fault finding and tracing cables when you have joined different colour coded cables together?

 

[The Crooner]

I bought a second hand loom from a much lower mileage car.

Apart from the routing being different, the integrity of the colour coding is maintained.

I am going to join the wires to the diagnostic socket, as that was not supplied, and three wires in the fuse box, as they were cut on the loom I bought.

Tony

 

[whipsey]

what sort of price is a new loom roughly?

 

[Brian Wales]

W124 engine loom/harness costs

Just going through the nightmare experience
of engine wiring harness loom problems....got quote from
local MB dealer of £716! ..and that's with discount!
so I went to local auto elecrics specialist who did a
rewire of the section that goes along the engine
(where the key problem is due to the high temps)
...cost £115 inc vat...but still got misfire!
however I can at least get the diagnostic
done now..have spent £ hundreds during past
2 years on all sorts of electical replacements
that I now find are due to the faulty wrirng harness
hope you have success

 

[kth286]

Hi Brian and welcome.

What 124 model do you have exactly ?

Where abouts you located ? Might be able to help out.