larryelmore

I purchased a 2013 ML 350 Bluetec from dealer inventory. While it had almost every option I could want, it did not have a trailer hitch. My needs now require that I it as an tow vehicle occasionally. When I went back to the dealer to price an MB hitch, they said that installation requires a replacement of the wiring harness for the dash to the back of the vehicle. Total cost approx $3000.
That seems like a step back in design and engineering. I was expecting that the trailer harness would simply plug in to the existing.
Am I off base? Does this really require a complete replacement of the wiring?

AS705

There are some related threads on this forum that speak to this issue and that may give further in sight, but in short the dealer installed hitch for the w166 is an expensive addition. Hopefully you can make it work.

fabbrisd1

The "complete" install requires a hitch, rear harness and wiring adapter, and a revised rear stability control unit. Some aftermarket installs by choice forgo the rear stability module.

Basic hitch and lighting/wiring setup should be around $1100, then the rear "SAM" module can be another $600.

Most dealers do not do the install - since the hitch is not MB but is sourced from aftermarket - but some dealers outsource to a local hitch installer who does the work and supplies the hotch/parts (dealer supplies the SAM) then I would guess that dealer seems to be upcharging/profit on the deal to $3K.

The BlueTech does take some wraggling since that AdBlue tank is back there - but still possible.

I would say start shopping around and find a true hitch/expert guy..

larryelmore

Thank you for your insight! I'll try and find a local qualified installer.

Cloudbuster

I just purchased a 2014 ML 350 Blue Tec with the Trailer Hitch. However there was no Ball Coupling, bolt or cotter pin included. Should these items been included? Kit is not much good without the ball coupling!

GregGebhardt

My Cayanne came with the tongue and ball but not the ML. It is not uncommon for this to not be included.

AS705

My understanding is that The last MY that this was included was 2012.

DUTCH

I think it's funny, since the Owners Manual is so adamant about only using the correct hitch that came with the ML.

Cloudbuster

Thanks for the reply. To me it would be like buying the ML but steering wheel is extras

GregGebhardt

I guess they figure you would get the one you want. There are different ball sizes and the tongues to choose from.

Also many never use their hitch, likely more than 50%.

Each of us have different expectations in our new purchase. When buying your tongue and ball do not forget the adapter required to for the flat type wire harness connector!

oreddie

In case you consider purchasing and installation from U-Haul (they advertise that have and can install a hitch on a 2012 M Class) please take note of my experience.

I went searching for a hitch for my 2012 M350 BlueTec class late last year after getting the OEM quote from my dealer. Using the U-Haul web site I found and ordered a Class 3 hitch and scheduled installation at my local U-Haul center.

Problem 1: After mounting the hitch the installer explained he couldn't wire it; no harness available for my rig.

Problem 2: Day after install, the AdBlue warning came on. I added DEF but the warning continued. Took to dealer. Hitch installer had lowered the rear of the DEF tank to install the hitch and, in the process, broke the connection from DEF tank to supply line. Crystallized DEF everywhere; $1400 repair.

Problem 3: Noticed a rattling noise from rear. Dealer found hitch installer had cut and removed a portion of the heat shield to install the hitch. Not enough shield left to properly attach it. Still rattles.

U-Haul has denied my claims so we're off to arbitration next.

Dealer related similar experience by one of their customers owning a GLK.

Ed
'12ML350 BT

Koenig1

Good luck in your case! I just recently installed a Curt hitch and wiring on my 2015 ML350. It wasn't the easiest, but pretty straightforward! Yes, you must 'trim' the heat shield, but I added 2 sheet metal screws to stabilize! Also, the instructions make note of temporarily removing the DEF support bar to fit in hitch, but caution to support DEF tank while base support is removed. Sounds like your installer was a bit of a lazy pig! The wiring is pretty straightforward, once you understand how MB's taillight plug works. I can share all of my work, wiring colours, part #'s, etc when I return from the cottage should anyone want. Also, once I finished, I relayed all my wiring info to Curt Manufacturing.... They were very happy with my info. One thing to note... Going aftermarket will not give you the stability control that the factory Hitch/SAM module will support! But... If you're stuck without a pre-purchased hitch, this is a good second! Total cost... $300.CAN

RCFRANK

I recently had a Curt hitch installed for my bike rack. At some point I will need to add the wiring. When you have time please post your wiring information.

Koenig1

Done...
https://mbworld.org/forums/new-m-cla...-bluetech.html

mwmak

I'm having the same issue with my hitch installation. They cut the heat shield on my 2015 ML 350 without letting me know they would need to do that and now there is a constant rattle and squeak that comes from it while I'm driving. I'm beyond upset because it's a brand new vehicle. I spoke with Repwest and they denied the claim. I know you said you had to go through arbitration what was the outcome?

The uhaul installation has been a pain since day one. They didn't have the part on time, then when I did take it in they stated they ordered the wrong part. Then I find out they didn't connect the wiring cables correctly, didn't even hook it to a power source. Another uhaul location from which I rented a trailer from went out of their way to fix it in the 100 degree Texas heat for 3 hours! I got the hitch installed at the San Antonio San Pedro location and they've been no help all they've done thus far is refund the $65 wiring installation fee.

I need to find out what to do since uhaul has denied my claim. They can't go around altering and damaging people's vehicles and not have repercussions. Help please?