2015 GLK 250 Trailer Hitch
I called Curt this morning about a load distribution set up. They said while it would work. It really wouldn't solve the light MB tongue weight issue. The load distro setup would transfer weight back onto the trailer. But the setup weighs in at 80 Lbs. It's meant more for a very heavy tongue on a larger truck to level out the trailer for better tracking. But has the side benefit of also reducing tongue weight a bit.
While on the phone I also asked about the electrical issue & how they mitigated the lights out warning on the new computer controlled systems on new cars. Their setup operates very similar to the old ignition timing lights. They use a totally separate power supply from the battery to power the trailer lights. And uses a relay system that just uses the tail lights as a trigger signal & not the power source.
Forgot to mention, I hooked up a trailer to my new Curt hitch & wiring. It was a U-haul trailer so was probably the worst case scenario as far as abused and shoddily patched up trailer lighting. I'm happy to report that the sun didn't go supernova, The sky is still in the sky, And my GLK worked fine with no faults or lights out reports and did not spontaneously combust.
PPS, I also called MB about the tow kit. It consisted of the hitch, Wiring & an extra duty cooling fan. NO OTHER MODS. No additional capacity trans coolers or engine radiators.
Last edited by super7pilot; Aug 8, 2015 at 01:27 PM.
Happy travels
There was nothing special about the install. The key ingredient in preventing a bulb out reading, Is to use a powered converter. It takes it's power from the battery and uses a trigger wire from the tail lights. It does not use the tail lights wires as the power source thus will not increase the load that the MB brain sees. Which is what triggers the fault reading.
The install was done by a local independent muffler/hitch shop. I did not lay a hand on the GLK. They ordered everything from a Curt supplier. The hitch is a Curt 13155 here is a link to the hitch. Just click on the install instructions and a PDF will down load for you to look at. LINK
I just have to vent and say this is the only car manufacture I've had nothing but lazy service techs and unwillingness to get at the root of a real simple small issues like this that are driving me insane.
When I'm done with this mechanical monster, it's back to the rice burners.
The Best of Mercedes & AMG
As an aside. I asked my dealer about installing the OEM MB hitch. They nearly choked on their coffee at the $3k + price tag of installing the factory hitch setup and were the ones to suggest an after market one with the converter.
To be honest with you & this has nothing to do with you personally CBR. Generally speaking, It's what we folks deserve for being so utterly lazy that we can't even be bothered to do a light check while sat in the garage where you can see if a light is out. No instead we want the car to check them for us, We also can't be bothered to look before backing up, Or doing a lane change. We have nannies do that for us.
Before long we will be complaining about having to wipe our own bums.
I'd also like to ask. Why go from a 450 to a 550? They can tow the same 7500Lbs but at a 10MPG penalty with the 550.
Last edited by super7pilot; Dec 1, 2015 at 05:17 PM.



