I have spoken to Etrailer.com. He had a explanation for me. The actual factory installed TBC acts just like the way i need. Potentiometer on the brakepedal and the TBC is an amplifier curuit to adjust the brakecharacteristics, but its brakepedal regulated.
If you order a trailer tow group, you will get a factory installed TBC since
years. Ford built in a TBC on F250 and above as a standardoption since 2010, i guess.
The problem is the way, how the TBC act.
The first TBC's act like a switch, brake on or brake off. The driver set a brakepower on the TBC and this brakepower is just set on or off, like the brakelights, just on or off. The brakepower on the trailer is not regulated. Always the same brakepower, doesn't matter how strong you brake.
The aftermarket TBC's are centrifugalsensors which don't have a connection to the brakepedal. If you brake, the centrifugal force sets the Brakepower on the trailer. If you brake harder, you get more force and so you get more brakepower on the trailer.
Only the factory installed TBC's act as a real controler with vehicleinformation.
I hope that informations are right.
So i "just" need to buy new hubs, discbrakeconversion, tubing and EoH-Actuator and i get the brake i need on the trailer.
240$ for Hubs, 650$ for 13" discbrakes with calipers, 650$ for the EoH-Actuator, Tubing 150$. ~1700$ for EoH Brakes.
I would also need new hubs for the 17.5" Rims, because we can't buy 235/80R16 Tires with a Loadindex of 3042lbs here in germany.
900$ for rims and 1000$ for tires.
1700$ is nothing against the 7000-8000$ for a german airbrakesystem.
So, the brakeproblem is hopely solved.
The wireproblem is also solved, i spoke to a shop 60miles away. I can use the installed wires, because the wirediameter is bigger than i need in cause of the higher american amperage.
The "germanisation" of the F250 with the needed 13pin wiring harness is about 3500$.
Nearly all problems are solved.
The next days i will sit down and do my financal maths and see what that all will cost together. But i think the figures will be a littlebit bigger than we first thought
We will see what is possible and what not.
Maybe we will wait for the transatlantic trading agreement. This will be maybe next or next-next year. Safes 22% customs. That would be nearly 24000$.
@Rgene7001
Of course it will be always a little bit more expensive and make a little bit more work to be unique. You decide to buy german vehicles instead of US vehicles.
My passat has the capacity to tow travel trailers up to 4400lbs and 165lbs on the ball. The german market is full of TT's with this weightlimit.
(We all use only rope-acting surge brakes for car-trailers, thats why we have the 7715lbs hardcap. And thats the reason why you can't buy a factory installed TBC on german vehicles and from germany imported vehicles like your ML's. And thats why we have a maximum legal GCWR of 15430lbs on all cars, if your car has 7715lbs GVWR and the trailer too.)
And of course i can go to the next dealer and buy a new or new-used TT today and have no problems. I have just to spend 40000-70000$ and drive home with a new TT. And have 15-20 feet livingspace.
If i roughly estimate the buy, import, custom and taxes and the conversion, the costs will be around 160000-180000$ for the hole combination.
But this is around the price which i have to pay only for a MB ML 350CDI. Without the TT. Cars to tow 7715lbs are extremly expensive. They are all luxury SUV's. A car can only two his own GVWR without a connected brake, thats a german law.
A compareable TV and TT combination would beat easily the 250000$, here in germany.