sl 600 wiring problems
 

I have a 93 sl 600.Has the same problem as most, asr light on , reduced power. I have put two new throttle bodies on and had the computer looked at and redone per the shop I took it to. This did not fix the problem, was told I needed a new wiring harness. Bought this and the shop returned the car to me saying they were not able to put on the harness after they had taken the old one out, firewall foreward. ( no I did not take it to a MB dealer which I have since found out was a big, big mistake, but at this point that is water under the bribge and a hard lesson learned.) I have since figured out where the wires went and have installed the old harness to its original place. Now the dilema!! Should I take the easy way out and cut the left air flow meter fitting off my new 2000.00 harness and splice it in since this is the only place on the harness that i can tell that the wires are bad? Or should I put the complete new harness in and cut the wires and splice the six wires going through the firewall( only reason I would do this is because I cannot figure any way to replace the wires under the dash without taking the whole dash out and I cannot get it out.). The third option and probably the best would be to replace the entire new wiring harness if someone can give me any direction as to how hard this is and if the dash has to come out to do this. Any help would be greatly appreciated. I would probably just park the car but it is pristine with only 18,000 miles on it. Thanks, Todd

Option #1 Absolutely not.

If you were able to put the old harness back in why cant you put the new on in instead. The old harness uses a bad insulation which goes bad. If you try to repair it you will only see this problem again. The new replacement harness should be made of better insulation.

Option #2 is not so bad as those wire going under the dash will not be so effected buy engine heat. But I would not recommend it.

Removing the dash is not too difficult. there are just alot of screws. The one place you will have to be careful is the two little dash speakers, which you cant figure out how to remove until you break one of them off so you can see how its installed.

I'm surprised this is so difficult. The 96 SL 600 wire harness is relatively easy. I believe the few wires that enter the car go to one, two or all three of the connecters shown in the picture and maybe the ground as well. These connectors should be acessable by removing the passenger side air bag. The picture is of a 96 SL600 so things might be different.

Now the chassie harness is an absolute nightmare.

Dashboard removal is also not to bad. Much easier than a 107.

John Roncallo

Thanks John,
First of all lets make sure I am trying to put in the correct harness. The one i have goes to the mass air flow meters and tons of other places. It has two sets of wires that go through the firewall that I assume go to the throttle controls. I am willing to put in the time to replace the whole harness if you can give me a starting point to take out the dash.(I put the old harness back in from the firewall foreward, the guy that was working on it couldn't get the dash out either so he gave me the car back with the harness torn out, firewall foreward). Is there a book that shows how to grt the dash out??Thanks, thanks, thanks, for all your help. todd

When you say tons of other places. Do you mean all on the engine, injectors ect with two big connectors going and 1 or 2 small connectors going into the computer box. Thats the engine wire harness. This is the way the 1996 is. Its not too bad.

If tons of other places means up and down the fenders and passes through the firewall on both sides. This is the forward chasis harness and it is a major pain in the ass on about the same level of pain as crucifiction. This wire harness does not include the mass flow sensors connectors on the 1996 SL600.

If its the major one that goes under the dash up and down both sides of the car. That is the mother of all wire harnesses. Pain lever would be about on par with the ending of the movie Brave Heart. This wire harness also does not include the mass flow sensors connectors on the 1996 SL600.

Removing the center console and the dash are not that difficult. You just need to know where all the hidden screws and bolts are. There were a series of step by step videos posted on the MBworld forum a while back. I saved them for myself, but there is no way to repost them in this forum and they are too large to send as e-mails. I believe the videos are part of the service CD which you can find for sale on ebay. Anybody have the link to the video's?

the harness I have sounds like the engine harness. It is part # 129-540-72-06. Checked with mercedes today and they do not sell a pigtail or part of a wire that will go onto the mass air flow .If you know where I could get one like you spliced in let me know. The cd or dvd sounds exactly like what I need. if you see one on e-bay let me know the listing # and I will buy it. Thanks

When I went to mercedes today they said they did not think the dash had to come out to put the engine harness in but they were not sure on a 600. Does anyone know if the dash must come out.

It didn't have to come out for the 1996 SL600. But I happened to have it off at the time. I believe this could be disconnected with removal of the passenger side airbag and cover only.

JR

Hi todd.
There are videos on how to remove the dash and other things.
Go there and download. :)
www.classic-roadster.de/modules.php?
Regards.
aam.

Thanks to all for the help. Will let you know how things work out. The videos should be a great help. todd