2015 GLK 250 Trailer Hitch
As the previous writer said : A larger Class MB would be necessary to pull an AIRSTREAM.

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What ever you do "DO NOT CUT" into the OEM harness! The one they supply makes it all plug and play into the OEM plugs that avoid the drama.
If you start splicing wires you're in deep crap!
Neighbor did it this weekend to his 2015 as he did not want to dig out the connectors from behind the trunk liner. Before he even did it the deed I said point blank to his face whatever you do "DO NO CUT" any of the OEM wiring. He did and guess what?
He came running over after and said his lights don't work. He took it to the trailer shop and they told him the same thing! Fuses are not blown. You're screwed! Next time listen to your neighbor.
He wanted to know how I knew. See what's between my ears. I know and told you and you did just the opposite you
'Big dummy"!
I suspect he blew the SAM?
He has an appointment with Mercedes on Wednesday!
He cut the ends off and just spliced his wires.
If etrailer sold you the correct one and one I saw was the part number. It should work.
I would follow the instructions to the "T" or have a professional trailer shop do it for piece of mind.
As far are pulling that Airstream. Many manufactures use the same type of transmission. All Automatic transmissions have coolers. Otherwise they would burn up. Some are built into the radiator some sit in front of the radiator, some to the side or at the bottom. Some have additional fans. Some are built bigger to accommodate the trailing package.
Every trailer package I've seen has some extra equipment to handle the extra weight. Bigger radiator, larger rotors, heavy duty springs, larger trans cooler, larger alternator, bigger battery.
Some have a hitch and harness and have no extra anything to support the added weight. Those are the ones to worry about. For the occasional tow OK, but not for the long distance tow and over and under to grandmas house! You'll never make it to grandmas. Well perhaps on the back of a flatbed!
http://www.curtmfg.com/masterlibrary..._App_Guide.pdf
Also available in excel format under trailer hitches and T connections
http://www.curtmfg.com/page/application_guides
I do not know if the MB GLK was a 350 (gasoline)or a GLK250 BT (diesel).
I did not precede with the installation because of the wiring for towing,trailer brake connection/ & the possible damage to my diesel exhaust system.
Further research & additional input feedback would be suggested.
If I ordered my 2014 MB GLK 250 BT from the factory ,the proper hitch & electrical harness would have been part of the assembly process.To my knowledge that portion of the assembly process is completed in Germany.An OK from the local MB Dealer is an opinion but if a problem with found in the electrical system & computer readings , I believe (opinion ) ,the MB dealer would not stand by the owner.After market decisions ,installations have their risks....yet , the owner will make changes that satisfy the pleasure of the vehicle owner.There are many fine aftermarket products that match the specific vehicle.
The key is the safe attaching of a trailer,or roof rack accessory... to prevent items from detaching or a trailer coming loose.
HONDO250 is 100% correct! I've seen too many people make stupid decisions and regret it later. Forums are good and not good. You should always follow what the manufacture states, period!
Also European and USA Benz's have different specs. Depending on where you plan to pull, you should follow what's in the glove box like I've stated above. Now is not the time to prove your made of testosterone and hose it up. Use the head on your shoulders.
Here is another one. I have a 2012 GL550. 100% stock OEM hitch that was installed at the factory or port. Along with the wiring harness. My trailers are both 100% LED. A few weeks ago I hooked up the trailer and decided to use my skis. Never made it out of the storage facility. The GL did not like the LED trailer at all. I got the hyper flashing lights and the idiot bulb out on the dash.
A trip to Mercedes was in order. I got nowhere with them. I called the selling dealer who knew of the problem, but did not nor would order the part to fix it. It was 100% aftermarket.
A trip to the trailer shop resulted in even better results but not solved yet! They claimed that they sold many trailers to Benz customers. Never had a problem. The trailer checked out as 100% functional without a problem. A call to Tow Ready an out fit that deals with trailer parts and wiring harness' yielded an adapter which had to be ordered. The part arrived. The hyper flash was cured but the bulb out remains. Another call to Tow Ready yielded another adapter as they though the one shipped might be faulty. This weekend will seal the fait of that one.
The trailer shop could place a resister in the Benz harness, but that would void the Benz warranty and any damage that resulted would be all mine to deal with. Adding the resister to the trailer itself might present problems for my other vehicles that tow the LED trailers and never had an issue.
The adapter that was purchased for 13.99 has a built in resister to combat the bulb out issues in VW, Benz, Audi and Porsche so says the manufacture.
I've had two other Benz and neither one presented this issue. Suggest before you hit the open road that you thoroughly check out the lights before you leave the lot.
The saga continues!
Last edited by super7pilot; Aug 7, 2015 at 01:27 AM.
I picked up my GLK in Sindelfingen. I watched the S-Class build line. They were building cars for all markets (left & right hand drive, EU, USA, Japan, China, Korea) all at the same time on the same line. I saw this with my own eyes. So no! Nothing is different in the basic chassis structure. The build differences from market to market are mostly pollution related.
I very highly doubt that in the litigation happy USA that several hitch companies would market a hitch system that could not handle the load that the OEM says that their vehicle can handle.
The issue with the computer seeing an "odd" load is the same for the factory tow wiring or an aftermarket. Electron are electrons, Resistance is resistance. No such thing as MB specific electrical theory. MB simply has already added the electrical components to "fool" the computer in the wiring that they splice in.
As an aside, My dealer has stated that they can indeed install the MB hitch kit (wiring included) on an already built GLK. They priced it out for me and it was ridiculous at $3,300. Gee now, I wonder how it is that they "add" that wiring.
I ordered my hitch with the original order. One of these days I'll figure out how to connect my U.S. GLK trailer electrical outlet to my German trailer (Anhaenger). Actually it's more likely I'll just re-wire the trailer and convert the lights to LED.
The problem in the "old days" was using a German (or other) trailer with "proper" dedicated turn signal and brake lamps versus a U.S. spec. vehicle that used the same lamp for turn signal and brake light. A dumb idea - just like using the same color for indicating braking and turning....
Last edited by MBKLUE; Aug 7, 2015 at 12:03 PM.



