wiring harness r129 sl500 94 - PeachParts Mercedes-Benz Forum

a2aa · #1 01-11-2005, 10:51 AM

AS I was backing out of my garage last weekend, my 94 sl500 with 44k miles car decided to sputter after 10 mins of smooth idling. It hesitated, the exhaust smelt like rotten eggs, and idling was rough. I decided to go back home and investigate. Due to the garage queen not being driven alot during the holidays might be the reason for it having PMS. After cleaning the throttle body plate and surrounding areas, it ran better than new!!

The only thing I noticed was the wiring harness was deteriorating ..I mean literally falling apart. HAs anyone replaced this on their r129?? I've read alot of threads on the W124's and W140's but none on the r129. Any experiences?

bwheitman · #2 01-11-2005, 11:01 AM

I replaced mine on my 96 SL 320. It is pretty simple. There is a big connector that plugs into the base module and I just started from the front of the engine. I removed the breather and the cover for the cabin filter, layed the new harness over the old one and just started unplugging the old connections and plugging in the new. After I go all the engine components plugged in I unplugged the old harness from the base module and plugged in the new one. It took about 2 hours, the most important thing is to take your time and be gentle. Good luck!!
Best Regards,
Brian

Jim's500E · #3 01-11-2005, 11:06 AM

I'm not surprised...I think those years for MB has shown us that use of inferior materials in their wiring has proved to be a bigger problem today, regardless of mileage and maint., especially on the M119 motor.

Fortunately, it isn't a big deal to replace the harness(es) yourself. Figure on maybe $500 to get it right again. I'd say if you want to keep the car for many years, then buy 2 and mothball one of them for future use...say 10-15 years down the road....I did that with that in mind.

bwheitman · #4 01-11-2005, 11:06 AM

Oh forgot to mention, that you should replace your harness as soon as possible, the problem being is that you will get arcing and it can cause your computer to fry. This happened on a friends 600 and it cost a bundle to repair. Get it before it gets you.

a2aa · #5 01-11-2005, 11:06 AM

Brian!!

Thankyou for the info. I see that you are from Texas as well. I belong to the Lonestar Austin section MBCA. Do you mind telling me where you got your harness from? The dealership is wanting $ 650 for the M119 version. Can't justify a bunch of wires with connectors to be over $500. Just hoping for alternative options to get it from. Again, thanks.

Jim's500E · #6 01-11-2005, 11:15 AM

Try Phil here also for the M119 harness(es)...the starter/alt one is only about 150$...the upper harness should be under $400.

My local dealer will give you a wholesale price on them if you are a MBCA member, and send them cheap if not free. 1 (800) 437-3361. Your dealer is gouging you with that price of $650.

a2aa · #7 01-11-2005, 11:34 AM

Thank you Jim!! I will break the piggy bank and "invest" on this harness ASAP!

Jim's500E · #8 01-11-2005, 11:56 AM

Sure, its no problem...this place exists to help each other out! Amazing isn't it how the prices on parts differ thru-out the country.

...but please don't cry poor with the fleet you list !!! I'm betting your piggy bank is a big fat sow.

a2aa · #9 01-11-2005, 12:10 PM

Thay are all rentals...

Thanks again buddy.

a2aa · #10 01-25-2005, 05:58 PM

Hey Jim,

Just wanted to thank you for referring me to your Benz dealership. Not only did they give me a 20% off list by being a MBCA member, they are shipping them free!!! The engine wiring harness total was $492. shipped! I went ahead and ordered parts for a timing chain R/R for my 560SL. And all of these are original MBZ parts!! They are awesome*( esp George) ..and so are you! Thankyou again.

For those intrerested, the number is: 1 (800) 437-3361

Jim's500E · #11 01-26-2005, 08:26 AM

Sweet ....I'm pleased they were able to hook you up and not make a liar out of me !!

Happy motoring man

a2aa · #12 02-22-2005, 10:29 PM

I just finished the replacement of the engine wiring harness on the sl500. It took me 2 hrs from start to finish- and that's with taking pics for a MBCA tech session for March. It's an easy DIY project.