R500 AND TOWING

NOT MUCH LISTED ON THE M-B WEB SITE ABOUT TOWING WITH AN R500. I WOULD LIKE TO KNOW IF THERE IS A TOW OPTION AVAILABLE, WHAT IT MAY CONSIST OF, AND WHAT IS THE TOWING LIMIT? THANKS FOR ANY REPLYS.

My dealer says the R350 can tow 2500 pounds with an aftermarket hitch they can have installed for me. The R500 can tow more, but I forget how much.

There is a tow bar that's available now from Draw-tite, and one from hidden-hitch for both the 350 and the 500. Both are class III, and are rated up to 3500 pounds and 350 pounds tongue weight. I haven't been able to find a wiring kit in the US, but did find one in Germany. Luckily I have family in Germany who can send it to me. These parts may soon be available at the dealer. Meanwhile, a local trailer company can splice into the wiring for the tail lights to make it work.

So, I bet you never would have thought you could get sex at a MB dealer.  When all was said and done, I got F-ed on this deal.  When I bought the car, the stealer said he could have a hitch installed for about $250.  The Hidden Hitch cost me about $125, and I installed it.  It wasn't as easy as I'd have thought, but it went on okay after a long struggle.  Took about two hours. 

As I said before, I got a family member in Germany to get the wiring harness and send it to me.  Plugged right in to the SAM and fuse box in the rear of the car, fit perfectly.  But, didn't work.  Half of the pins had +12v, all the time.  I called the stealer who said it needed to be programmed in the computer and would cost about $50.  Okay, fine.  Well, two hours after I dropped it, they called asking if I had instructions with the harness.  no.  Two hours later they said it needed a new SAM for $300 plus the labor.  Well... okay... this was gonna sting. 
 
All said and done, after they installed the new SAM, that didn't work either.  So, they tried to plug in the ML harness, since it looks the same.  Didn't work.  Then, they put the original SAM back in, plugged in the ML harness, and voila!  We have a winning combination.  So, I didnt' need the SAM, and really didn't need all that diagnosis either.  Lesson learned the hard way is... get the wiring harness for an 07 ML, plug it into the fuse box and computer, and all should be golden.  I have not yet towed with it... will probably take a test-tow later this evening and tow the snowmobiles to the gas station to fill up, just to make sure it all works well.  So you know, that harness is $185 and doesn't include the 7-pin to 4-pin adapter.  MB will charge another $30 for that, but you can get one at Home Depot for $7.
 
I think they should pay me now for letting them use my car to figure all this out.  Sales manager says he will help offset some of this cost... we'll see what happens.  The senior technician tells me that when I connect the trailer, the R should know it's there and will adjust the tranny, brakes, traction control, throttle response, everything to the right settings for a trailer.  If the SAM doesn't tell the main computer, the adaptive qualities of the tranny and brakes will adjust within a few miles of starting to tow.  Again, we'll see... but sometimes all those sophisticated electronics make things a lot harder than they need to be. 

Now that I spent all this money setting it up to tow, and it took 8 months of my 27 month lease... I guess I will have no choice but to buy this thing at the end of the lease, or it won't feel like it was worth the effort!  You should be able to learn from all I did to figure this out, and if you do it yourself, you can get the hitch and harness for about $300, and install it all in a few hours.  Oh, and one other thing... they sold me (for $9) a bracket that holds the wiring harness connector next to the hitch.  The bracket comes from the ML kit, and they used a few screws to attach to my hitch setup.  You don't absolutely need this part, but it makes the installation look much more professional.
 
Good luck, and hop you enjoy your R Class!

By the way... anybody want to buy a german trailer wiring harness?  lol 

Sounder need some help on getting my r500 tow package working. Looking for plug from the Sam unit to the trailer plug. I know you said try a 07 ml wiring harness but I can''t seem to locate a part number to order it from Mercedes. Can you help??? Desperate please contact me at 818 482-5877..Thank you,
Dave