[cgeaves]

Anyone have any knowledge of hooking up a trailer wiring harness to our 235's that will work. I own a 2014 M235i that I have installed a hitch on that I use for a bike carrier. I also have a small utility trailer so I used a multi-tester to determine which wires to tap into for left/right blinker, lights, & brakes. The wiring harness has indicator lights on it that confirm the harness is hooked up correctly when I turn on my blinkers, brake, etc. however when I connect to my trailer everything goes haywire! The right tail light goes out, the blinkers don't work. Ultimately I went by the dealership to ask for their help and here's what they told me. They don't make a plug-n-play wiring harness for the M235i which didn't surprise me because they don't make a trailer hitch either. The only harness they sell is for the X series suv's and he said that won't work on my car. The problem is that all of this is computer controlled now and when the computer senses increased resistance when hooked up to the trailer it freaks out. Even with the X series they have to use the wiring harness and then run some software to tell the computer about the increased resistance. Apparently that is the big issue because I have it wired correctly.

I know there are not many who are pulling trailers with their 235 but does anyone know of a work around for this issue?

[nike001]

I doubt it.

I think you bought the wrong car if you're worried about towing things... lol

[Heitzer]

I used the Modulite Vehicle Wiring kit (119147KIT from trailer.com). My BMW dealer installed it and it works perfect. Its pretty easy to splice into brake lights for a DIY also and connecting to the battery which is in the trunk anyway..

I tried a harness made for the 2 series in Germany. Newer got it to work because it requires communication and registration with the car and BMW doesn't allow it for the M235i.

I tow my BMW sport bike to the track. A perfect combination in my opinion .

[cgeaves]

Originally Posted by Heitzer

I used the Modulite Vehicle Wiring kit (119147KIT from trailer.com). My BMW dealer installed it and it works perfect. Its pretty easy to splice into brake lights for a DIY also and connecting to the battery which is in the trunk anyway..

I tried a harness made for the 2 series in Germany. Newer got it to work because it requires communication and registration with the car and BMW doesn't allow it for the M235i.

I tow my BMW sport bike to the track. A perfect combination in my opinion .

This is great info Heitzer. What you experienced with the harness from Germany sounds like what the dealership told me here in Louisiana. Interesting that the Modulite Vehicle Wiring kit worked and didn't require anything more to be done to the computer. Do you suppose the dealership did something more after they wired it in? I typed in trailer.com and it takes me to U-Haul and doesn't recognize 119147 Kit. However I googled that number and found this on Amazon.

http://www.amazon.com/Tow-Ready-1191.../dp/B00ASY29C0

Is this the module you used?

[mdputnam]

I think that was a typo. It's www.etrailer.com that he was referring to. They have the harness too.

[cgeaves]

Originally Posted by mdputnam

I think that was a typo. It's www.etrailer.com that he was referring to. They have the harness too.

Nice confirmation. Thanks mdputnam! I'll probably give this a try. I know my harness had no power wire. That may make the difference.

[Heitzer]

Ups..sorry. Meant etrailer.com Stupid autocorrect.

[hoppy6698]

Originally Posted by cgeaves

This is great info Heitzer. What you experienced with the harness from Germany sounds like what the dealership told me here in Louisiana. Interesting that the Modulite Vehicle Wiring kit worked and didn't require anything more to be done to the computer. Do you suppose the dealership did something more after they wired it in? I typed in trailer.com and it takes me to U-Haul and doesn't recognize 119147 Kit. However I googled that number and found this on Amazon.

http://www.amazon.com/Tow-Ready-1191.../dp/B00ASY29C0

Is this the module you used?

eTrailer recommended 119250 Kit for M235i. Is the link above at Amazon the right one?

[MikeG12]

For our new X1 I ordered the following item:
http://www.etrailer.com/Custom-Fit-V...119250KIT.html

This just clamps around each wire and has a separate power lead going directly to the battery. No connection at all to the car wiring, just couples inductivily. Should be easy to install on the 235 because the battery is in the back. On the X1 the battery is in front so you have to route the power wire the length of the car.

[3.0L]

Originally Posted by cgeaves

Anyone have any knowledge of hooking up a trailer wiring harness to our 235's that will work. I own a 2014 M235i that I have installed a hitch on that I use for a bike carrier. I also have a small utility trailer so I used a multi-tester to determine which wires to tap into for left/right blinker, lights, & brakes. The wiring harness has indicator lights on it that confirm the harness is hooked up correctly when I turn on my blinkers, brake, etc. however when I connect to my trailer everything goes haywire! The right tail light goes out, the blinkers don't work. Ultimately I went by the dealership to ask for their help and here's what they told me. They don't make a plug-n-play wiring harness for the M235i which didn't surprise me because they don't make a trailer hitch either. The only harness they sell is for the X series suv's and he said that won't work on my car. The problem is that all of this is computer controlled now and when the computer senses increased resistance when hooked up to the trailer it freaks out. Even with the X series they have to use the wiring harness and then run some software to tell the computer about the increased resistance. Apparently that is the big issue because I have it wired correctly.

I know there are not many who are pulling trailers with their 235 but does anyone know of a work around for this issue?

Sacrilege.