Engine harness replacement for '92/'93 500SL

[LeaUK]

Hi all

Long time no see I know but the time has finally come to change the harness (due to intermittent ASR light and visual inspection of my harness) and I've been looking through many pages here including the DIY section, but just can't locate a few things. If someone could point me in the right direction it would be very much appreciated:

1. Where can I purchase the wiring loom from (preferably in UK, but no harm in shipping from Phil if he carry's stock)

2. I see there are upper and lower parts - rough cost for individual and both?

3. I guess I should do both?

4. Does the Electronic Throttle Actuator (ETA) unit connect to the new harness? If so, I seem recall from memory I need to strip the ETA out also and rewire this manually. Does anyone specialise in this repair - I seem to recall a few US places but anyone know of any UK based?

Many thanks
Lea

[Roncallo]

Originally Posted by LeaUK

Hi all

Long time no see I know but the time has finally come to change the harness (due to intermittent ASR light and visual inspection of my harness) and I've been looking through many pages here including the DIY section, but just can't locate a few things. If someone could point me in the right direction it would be very much appreciated:

1. Where can I purchase the wiring loom from (preferably in UK, but no harm in shipping from Phil if he carry's stock)

2. I see there are upper and lower parts - rough cost for individual and both?

3. I guess I should do both?

4. Does the ETC unit connect to the new harness? If so, I seem recall from memory I need to strip the ETC out also and rewire this manually. Does anyone specialise in this repair - I seem to recall a few US places but anyone know of any UK based?

Many thanks
Lea

I'm speaking from 1996 SL600 experience, so there may be differences.

You should be able to purchase at any MB dealer. No one will have this in stock.

As far as I know the only lower parts are the oil pressure and level and alternator, starter harness. I wouldent see a need for both except the lower one is probably under $200 US the upper is probably over $2000 US.

I don't have ASR, I have ESP which has its own separate harness.

I'm not sure what you mean by ETC (Electronic Transmission Controller?) The wire harness connects directly to the ECU (Engine Control Units) Thats the LH units for pre96 and the ME units for 96 up. I was unaware that your car, pre 96 SL 500 had an electronic shift transmission. If it does it is not connected to the engine harness.

In my case the connectors for the ECUs just unplug from the top of the two ME units and are easy to remove. I think your connectors are on the bottom of the box, but my guess is they come out as a separate connector.

For the 1996 SL600 this appears to be a very simple job. Remove 3 connectors from the computer box and disconnect everything from the engine. which all seems to be very exposed, accept I cant say the knock sensors are easy to get at. They might require removal of the intake manifold.

[LeaUK]

Hi John

Thanks for all your comments, yes sorry the ETC was a typo - I've corrected that. I have the infamous ASR light syndrome which is indicative of either potentiometer wear in the ETA unit itself, or/and ETA wire insulation breakdown. In fact today I inspected a few wires connecting to the variable camshaft solenoids and indeed they show the classic insulation cracking!

As I need to remove the manifold to get to the ETA (should I replace the gasket also?), I thought I'd change the loom, but at $2000 that's not pleasant!

Oh and forgot to mention that my 500 is an LH with semi electronic gears.

I wonder if there is a step by step guide re loom replacement? Also I'm sure there's a huge thread on here regards to rewiring the ETA, but I'm hoping there are a few UK companies who now offer this as a service - a new ETA is 1000UKP!!!

[deanyel]

No need to do the lower until you see a problem there, unless you just want to. In the U.S. the upper harness should be around $600 for that car, not a difficult DIY job.

[Roncallo]

Originally Posted by LeaUK

Hi John

Thanks for all your comments, yes sorry the ETC was a typo - I've corrected that. I have the infamous ASR light syndrome which is indicative of either potentiometer wear in the ETA unit itself, or/and ETA wire insulation breakdown. In fact today I inspected a few wires connecting to the variable camshaft solenoids and indeed they show the classic insulation cracking!

As I need to remove the manifold to get to the ETA (should I replace the gasket also?), I thought I'd change the loom, but at $2000 that's not pleasant!

Oh and forgot to mention that my 500 is an LH with semi electronic gears.

I wonder if there is a step by step guide re loom replacement? Also I'm sure there's a huge thread on here regards to rewiring the ETA, but I'm hoping there are a few UK companies who now offer this as a service - a new ETA is 1000UKP!!!

Well the last person who posted says $600. Thats a good deal if its true. I'm only going by the $1700 price I got for my 1986 560SL not nearly as complex, but they dident have such a huge replacement campaign for those.

There is a step by step for other cars in the DIY links.

On my 96 SL600 the transmission is electronic and the trans wire harness is separate and does not connect to the main wire harness.

I should be in wire harness hell all day today. Or should I just stay inside in the cool air conditioned house.

[LeaUK]

$600 - now that's more like it. Has anyone got a link to a supplier - pref one that ships to the UK?

I new Jim (http://pages.prodigy.net/jforgione/MB_S500.html) had some excellent pages covering ETAs and it seems my low oil pressure issue - now I found his site again - thanks Jim!

Also, it seems like I don't need to remove the manifold to get the ETA out - that's handy ;-)

My father-in-law happens to be a mechanic (has been for over 50 years) so if it's s DIY job then it going to be OK I think.

He recommends that I locate all the parts first then we can review and fit

[deanyel]

Part number is 129 540 77 05, list is $745, which is the very high end of the 119 wiring harnesses, most are more like $600-650 list. It's a dealer part, just need to call the usual suspects, Duval, Caliber, Park Place, ask for the best price, expensive parts are often negotiable. Phil doesn't list it but may be able to get it. $669 here - http://www.trademotion.com/partlocator/index.cfm?siteid=214269 , enter part number, i.e. 10 percent off, but other than that no links, just need to make the phone calls. Not sure about the international shipping.

[LeaUK]

Thanks for the part number deanyel. Do you think there will be a difference between US and UK part numbers?

I'll try my local dealer first (for a laugh), then hit the US ones I think. I'll ask Phil also, but he seems to have a ban on international shipping which seems rather odd?!

Lea

[deanyel]

Originally Posted by LeaUK

Thanks for the part number deanyel. Do you think there will be a difference between US and UK part numbers?

I'll try my local dealer first (for a laugh), then hit the US ones I think. I'll ask Phil also, but he seems to have a ban on international shipping which seems rather odd?!

I would think part numbers are the same but you just have to get yours. No part number changes according to EPC so you could try to get it off the car too, near the source plug. You may run into more bans on international shipping, not sure, MB sure doesn't like dealers selling cars across borders.

[LeaUK]

especially when 2USDs = 1GBP

Great, it's actually on the loom eh, that will definitely make things a little easier.

You mention the source plug, I took a look around in the engine bay today but couldn't find it but I'm assuming it's a the rear of the ECU aluminium case?

Lea

[deanyel]

Should be somewhere in the right rear of the engine compartment - should be able to trace it backwards from the wires to the injectors.

[LINDS HANSON]

Just order the loom from the dealer, I just bought one for £481 less 10% pt no.1295401706 Its dead easy to fit about 1.5hrs Regards Linds

[LINDS HANSON]

The loom connects to the side of the ECU alloy box, The box or ECU do not have to be removed as there is a link harness from the side of the ECU box to the bottom of the ECU

[Terry McNeilly]

I did mine last year. Both the harness and a new Throttle Actuator. The Job is pretty straight forward. Just lay out the new harness on the engine before you remove the old one to get a better idea of the routing. Be extremely careful with the throttle body remove and replace though. I managed to bump the hot wire sensor and it cost me another $900 to have the diagnosis and repair.....

Phil did me right on the harness and ETA.

[omegabenz]

Try www.speed-autoteile.com in Berlin for your harness, they have good prices.

Most US dealers wouldnt ship to you directly, you would need a middle man.

I am going to order a harness for my 500E. It is really falling apart. =(