OEM Hitch Wiring, anything else needed?

[treimche]

I need to add the OEM BMW hitch wiring to my 2012 X5 35i. It came with a Reese trailer hitch already installed, but no wiring.

Is this the correct part number for the wiring? 71602156526 when I look at that part on ECS website, it says not compatible, but it also says its for E70 X5. https://www.ecstuning.com/b-genuine-...s/71602156526/

Besides the wiring, is there anything else I need? I have a trailer brake controller from a previous vehicle that I can wire in and use.

[andrewwynn]

After an hour of searching I found the exact part number listed at bimmerworld and all e70 models confirmed fitment.

I will eventually get the kit and add lights to my carrier rack so I can have proper DSC when towing and no continuous alarm when backing up.

I'm not exactly sure what is included when your X5 is prepped for adding trailer hitch. The kit includes the entire harness the only thing I saw in research if car is not prepped for trailer you need to cut a hole in the"fuse box" to fit the trailer control module but you could just zip tie it anywhere it fits.

[andrewwynn]

I added a 4-pin trailer harness for about $90 it works perfectly ok and I keep it in the left storage area when not towing. You should check if PO did the same.

I discovered when installing the wire taps for the aftermarket wiring that the PO had installed but removed the identical type of wiring kit (the wire taps were still on the wires)

[treimche]

Originally Posted by andrewwynn

I added a 4-pin trailer harness for about $90 it works perfectly ok and I keep it in the left storage area when not towing. You should check if PO did the same.

I discovered when installing the wire taps for the aftermarket wiring that the PO had installed but removed the identical type of wiring kit (the wire taps were still on the wires)

Previous owner of mine didn’t do anything with wiring. He only used the hitch to carry bicycles. I have a car trailer and a small boat so I need 7 pin wiring.

[ard]

Out of curiosity, why do you need a '7 pin' connection?


If you want the car to control the trailer brakes (which AFAIK is the only added benefit of 7 over 4 pin)you need a brake controller in the car (in addition to OE factory wiring and modules)





I *really* like the Tekonsha product line. I tow pretty heavy loads with my truck (11k to 14k lb goosenecks) and they are flawless. Edit: by truck, i mean F250 PSD 4x4..not the x5


Some ntoes:
The "bmw branded" under dash brake controller *is* a Tekonsha P2 (or p3?)...problem is that you need to run wiring from the rear up to the dash. Not hard, but it will be time consuming. You can buy pre-made harness and all that, so no splicing. etrailer sells an OEM version:
https://www.etrailer.com/multi-produ...BMW&HHModel=X5
(here 'OEM' is 'just like the BMW OE version... clearly Tekonsha is the OEM for the BMW branded controller, so a Tekonsha controller IS an OEM controller.... )



Tekonsha makes a 'wireless' controller that pairs to a phone. https://www.tekonsha.com/product/909...l-proportional...
I WOULD NOT GET THAT. I dont need my braking relying on an iphone!


Tekonsha makes an RF brake controller.
https://www.tekonsha.com/product/902...l-proportional
This sits at the rear- basically between the cars '7 pin' and the trailers 7 pin.... You then have a 'controller' that sits under the dash, plugs into a cigarette lighter (or hardwire) that acts as just an interface to the brains and controller that is in the back. (I am pretty sure that after you get it all set up, set the vaules for type of braking, sensitivity, etc) you could REMOVE the interface that plugs in up front and the controller itself in the back will control the brakes just fine. In other words, no 'mission critical control fuctions' are being transmitted via RF while it is running. I THINK. Verfy this.


If I didnt want to run wires (personally this doesnt trouble me) Id get the RF and do a bit of a custom install inside the rear wheel well. ie not hang it outside on the hitch.


Finally anything more that 1500 lbs you want a brake controller (at least here in California). BMW is kinda sneaky about towing capacity and when you need a brake controller- the do NOT sell a car with a hitch. And they speak of hithc ratings mostly. Ive never seen a GVWR or CGVW for an X5 w trailer... FWIW.

[andrewwynn]

Def go with the OEM hardware. The research I found today finally confirmed that kit at ecs is same for all e70.

Also: of you look at the PDF find where it says to put the trailer module. If there's a spot to hold it and the clip I think you are "prepped"

You will need to code for trailer. I think bimmercode can do it

[treimche]

Yes I have read somewhere else too that I will need to code the vehicle for the trailer wiring.

I need 7 pin wiring because I have a car trailer with trailer brakes that I will pull with the X5 once in a while, short distances. And I already have a nice trailer brake controller from a previous vehicle, so I can just use it, and run wire to the rear. Not a big deal for me.

[jimoreno]

I have the harness and the hitch but now there is one last open item. For those that have used aftermarket hitches (non-BMW) I have a question. What did you do with the wiring connector for the trailer? There is no mount for it so it has to go somewhere. Not sure if mounting a plate to the hitch to them mount it or somewhere else from the collective knowledge here.
Feel free to post pictures of the mounted connector.

[treimche]

Once I get around to installing the wiring, I'm going to look at my hitch to see if something like one of these will work:

https://www.amazon.com/gp/product/B0...KIKX0DER&psc=1

https://www.amazon.com/gp/product/B0...e_8?smid=&th=1

[andrewwynn]

I like the second one but it says unavailable


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