Brake controller for E70 experiences

[bluvalley]

Hi,

Have my new 08 x5 with factory hitch installed. I found the empty connector for the tralier brake controller but the 4 wires are not labeled to correspond to the 4 wires on the brake controller.

Anyone have an idea of how to find this information?

thanks,

bluvalley

[pebbrb05]

Originally Posted by wsanchez

HoustonMtn, M3Armand:

The E70 is technically pre-wired for a brake controller.

The problem is that the connector is in the rear compartment in the panel on the right side, and the brake controller needs to be where the driver can reach it (front left). That means I had to run a wire bundle from under the steering wheel (where I put my controller) to the connector in the panel in the back.

This is an improvement over the E53, where, I'm told, one has to run wiring down to the trailer connector itself, which is more work.

An update on my situation: I've towed our 16' Airstream (3,500 Lb. GVWR) a couple of times now from San Francisco to Reno (over the Sierras) using the weight distributing hitch that I got with the trailer, and it's great. I've never noticed any sway, and I've never felt like the X5 was working very hard to pull the trailer. Granted, it's not a very heavy trailer, but it's easy to forget it's back there until you look in the mirror.

I plan to purchase an Airstream 23 FB with 4757#UBW and 500# hitch weight as soon as I get the brake controller issue worked out. After sending your info to my local BMW dealer I got a response that "this is something that we cannot get into. A hitch company would be the best to handle this."

Could you post pictures of the rear compartment connector and the manner in which the wiring was routed to the front left driver area? In addition, which controller by brand did you install? Thanks in advance.

[bluvalley]

The plug for the brake controller is attached to the wires in the right rear panel, you might need to reach in pretty far to find it. It's got a small plastic bag attached with a plug inside. BMW does not have the wires labeled.

The brake control wiring needs to be run from here to the dash. I would not accept an answer like that from your dealer about the install, if they installed the hitch than they should install the controller. My dealer was not thrilled about it either but I pressed them on it and they did a really nice job, one of the service guys knew all about controllers from installing them in his pickup.

The total cost was about 350.00. The controller I have is the Tekonsha Voyager, they do not recommend the more advanced Prodigy model because of the X5's complicated electronics.

I don't have a pic of the wiring bundle but I've attached one of my X5 and Airstream.

Good luck

[Mabuhay]

Originally Posted by HoustonMtn

A weight distributing hitch transfers weight away from the rear axle. Some is transfered to the front axle of the vehicle and some to the trailer axles. You were told right, wsanchez, they are safer.

I can't pretend to be inside their heads at BMWNA, but here's a theorem: IF they rated it to pull 6K AND the only way to pull a 6K trailer is with brakes, THEN a surge brake equipped trailer is the only option left. This negates the use of a weight distributing hitch. Which seems to be the way they do it in Europe.

Houston, can you explain how a "weight distributing hitch" works? I understand from your description above that it transfers weight AWAY from the rear axle. I assume this means rear axle of the X5 and not the trailer (sorry if dumb question). So I am having a hard time understanding how could a device "transfer" weight. If the weight distribution of our X5 is 50/50. This is telling me that this hitch can make it 60/40 or so? I'm wondering how does it do so mechanically. And why would this be a safer setup?

[JCL]

If you look at the picture above your post, around the hitch ball, you will see the equalizing bars coming back from the hitch (not the electrical hookups, which are looped in the same location). They are under the trailer A-frame, and are about 3' long. Think of those bars like wheelbarrow handles. If you lift on them, you will raise the back of the vehicle, and transfer load to the front axle. Those bars are lifted by being connected to the front of the trailer, on the A-frame. They can swivel left/right, so the trailer can turn corners. But by tensioning them, pulling them upwards, load is transferred off the rear axle, to both the front axle and the trailer axle.

The X5 doesn't have 50-50 weight distribution except when it is empty. Putting a load in the back of it, or a heavy hitch load on it, changes it towards your 40-60 (F-R) number, although I don't know what the actual distribution would be. A weight distributing hitch helps shift it back closer to 50-50, although you won't likely get right to the empty weight distribution %.

[pebbrb05]

Originally Posted by bluvalley

The plug for the brake controller is attached to the wires in the right rear panel, you might need to reach in pretty far to find it. It's got a small plastic bag attached with a plug inside. BMW does not have the wires labeled.

The brake control wiring needs to be run from here to the dash. I would not accept an answer like that from your dealer about the install, if they installed the hitch than they should install the controller. My dealer was not thrilled about it either but I pressed them on it and they did a really nice job, one of the service guys knew all about controllers from installing them in his pickup.

The total cost was about 350.00. The controller I have is the Tekonsha Voyager, they do not recommend the more advanced Prodigy model because of the X5's complicated electronics.

I don't have a pic of the wiring bundle but I've attached one of my X5 and Airstream.

Good luck

Thanks for the info. Will take a look. Which Airstream are you towing? Any issues towing? What mirrors are you using?

[Mabuhay]

Originally Posted by JCL

If you look at the picture above your post, around the hitch ball, you will see the equalizing bars coming back from the hitch (not the electrical hookups, which are looped in the same location). They are under the trailer A-frame, and are about 3' long. Think of those bars like wheelbarrow handles. If you lift on them, you will raise the back of the vehicle, and transfer load to the front axle. Those bars are lifted by being connected to the front of the trailer, on the A-frame. They can swivel left/right, so the trailer can turn corners. But by tensioning them, pulling them upwards, load is transferred off the rear axle, to both the front axle and the trailer axle.

The X5 doesn't have 50-50 weight distribution except when it is empty. Putting a load in the back of it, or a heavy hitch load on it, changes it towards your 40-60 (F-R) number, although I don't know what the actual distribution would be. A weight distributing hitch helps shift it back closer to 50-50, although you won't likely get right to the empty weight distribution %.

So to check my understanding, the "weight distribution hitch" is made to shift the weight OF THE TRAILER...towards the front axle or rear axle OF THE TRAILER. i.e. - your wheel barrow analogy (which helped a lot, btw if my understanding is now correct).

I think the thing that's been throwing me off is when people refer to "vehicle" vs. "trailer" vs. "X5". For example, Karlbalmer states "may be that it transfers too much weight to the rear of the veh." I guess in this case, "veh." means "trailer".

When Houston says, "A weight distributing hitch transfers weight away from the rear axle. Some is transfered to the front axle of the vehicle and some to the trailer axles. You were told right, wsanchez, they are safer."

I assume he means "A weight distributing hitch transfers weight away from the rear axle OF THE TRAILER. Some is transferred to the front axle OF THE X5 and some to the trailer axles..." So this one doesn't make sense in that how the hell does it transfer weight to the front axle of the X5? Houston...we have a problem... (sorry, I couldn't resist!).

[JCL]

Originally Posted by M3Armand

So to check my understanding, the "weight distribution hitch" is made to shift the weight OF THE TRAILER...towards the front axle or rear axle OF THE TRAILER. i.e. - your wheel barrow analogy (which helped a lot, btw if my understanding is now correct). Correct

I think the thing that's been throwing me off is when people refer to "vehicle" vs. "trailer" vs. "X5". For example, Karlbalmer states "may be that it transfers too much weight to the rear of the veh." I guess in this case, "veh." means "trailer". No, he meant the X5, but he had it backwards

When Houston says, "A weight distributing hitch transfers weight away from the rear axle. Some is transfered to the front axle of the vehicle and some to the trailer axles. You were told right, wsanchez, they are safer." Absolutely correct.

I assume he means "A weight distributing hitch transfers weight away from the rear axle OF THE TRAILER. No, he means the rear axle of the X5 Some is transferred to the front axle OF THE X5 and some to the trailer axles..." So this one doesn't make sense in that how the hell does it transfer weight to the front axle of the X5? By lifting the back of the X5, applying a torque load that pushes down on the front axle of the X5 and pulls up on the rear axle of the X5. Houston...we have a problem... (sorry, I couldn't resist!).

The thing to remember is that you can't believe everything you read on the internet. You mistakenly assumed that every post was logical.

[HoustonMtn]

My BMW dealer was kind enough to run the blue (brake control output) wire for me when I had my hitch installed. This wire runs from the back of the vehicle to the dash area above the driver's knees. Sorry, but I can't give more details on that. The rest of the job was mine. They would not install the trailer brake controller.

I chose a Prodigy P3. I made the connection to the lighting control module to pick up the brake light signal (see the FAQ's on this website). I've attached a photo of that connection which is located in the passenger side kick panel below the dash. I removed the interior trim pieces from the passenger footwell and fished the wire through from passenger to driver's side. Very simple.

The remaining connections were made (+12V and ground) and the control was mounted to the driver's side dash as shown in the other photo. I'm not entirely happy or unhappy with the location I chose. It's easy to bump your knee on when getting in. But I also wanted it to be easily reachable with my non-dominant hand in case I had to apply trailer brakes independently. It's also easily visible to verify proper functioning. The P3 mount allows you to quickly detach the controller and remove it when not in use.

[tdg]

Man, you guys have driven down the path I just started and have answered some questions. I have a 2007 4.8l X5, which has a 2" factory reciever installed (it has a 7 prong electrical connector - but as far as I know, only 4 wires are connected). I had it installed when I purchased the X5 to pull my small 10' cargo trailer (which has a hydrolic surge brake).

Now I just purchased a travel trailer (Coyote Lite CL232SS - 4665lbs UVW dry and is 27' hitch to bumper - brochure pic below). I also had the dealership (Calgary) tell me that they would not have anything to do with installing an after-market brake. I will head back and press them to ensure the wiring is run to the front. The RV dealer seems to have no issues installing the brake - even on a BMW. I also purchased a 750# Blue Ox SwayPro which functions for both weight distribution and sway control. I will need it for pulling in Alberta & BC (windy on the prairies and in the mountains).

I will let you know how the wiring & brake installation goes, as well as how the sway bar works and the old gal pulls. The pics above for the wiring are very helpful. Thanks.