Trailer wiring info for MY09

[Grum]

Hi there,

I'm looking to tow a camper trailer behind my MY09 and need to hook up an electric brake controller and axillary hot wire to power the lights and recharge the camper trailer's internal battery.

At present I have the Subaru genuine tow hitch and wiring fitted (part number L101ASC000). After looking around, I want to get a Tekonsha Prodigy electric brake controller.

The Tekonsha product literature mentions that many vehicles have a special plug for connecting an electric brake controller that is located near the steering column, for which a cable can be purchased from the vehicle manufacturer. I would like to know:
1) Does the MY09 have an electric brake controller plug located near the steering column?
2) Is there a Subaru cable for this plug? Can I find out the part number to order it?
3) Alternatively, if the plug exists but no cable can be purchased, can I find out the wiring details for the plug?

In the flat 7 pin trailer plug at the vehicle rear, all pins are currently connected to wires. If an electric brake controller plug is not provided near the steering column, I would like to know:
4) Where do all the wires for the plug terminate?
5) What are the details for these wire terminations?

In fact, ANY hints on where I could get this info would be great. The Subaru servicing guys flatly denied the trailer plug was fully wired, even though I had seen it with my own eyes!

Cheers, Grum.

 

[Barry]

Hello Grum, and welcome to the forum.
My 05 Outback has a flat cable to the trailer plug, so it should just be a matter of finding the other end of that cable and tracing the relevant wire.
The standard wiring (Aus, not sure elsewhere) is for the blue wire to socket / pin 5 to actuate the bakes.
I will be replacing my car socket in the next few days, so will post regarding what I find - i.e. whether the flat cable contains a blue wire connecting to socket 5.

 

[Barry]

Grum,
I've just commenced to replace the flat socket block on my 05 Outback and it clearly contains the BLUE wire for the brakes on socket 5, as per my previous post.

 

[ian059]

Typically, when the 7 pin flat socket is supplied, it has all the wires connected. What usually happens when the socket is wired to the car, the blue and black wires are terminated because they are not used for normal trailer towing. Follow the seven core cable back to where there are wired to the vehicle wiring and you'll find the black and blue wires are not connected to anything.

If you want to connect to your camper trailer battery you will need heavy 10 amp dual core cable and an anderson plug, not the 7 pin trailer plug.

IanC

 

[Barry]

If you want to connect to your camper trailer battery you will need heavy 10 amp dual core cable and an anderson plug, not the 7 pin trailer plug.

IanC

Good point Ian, I had meant to comment on that. I am wiring mine with twin core 'house flex' (240volt) to an Anderson Plug at the back of the car, to match the Anderson Plug on the camper trailer.

Typically, when the 7 pin flat socket is supplied, it has all the wires connected. What usually happens when the socket is wired to the car, the blue and black wires are terminated because they are not used for normal trailer towing. Follow the seven core cable back to where there are wired to the vehicle wiring and you'll find the black and blue wires are not connected to anything.
IanC

I checked my old socket while attaching the new flat socket block today, and two wires have been terminated before the sockets. (I will post an additional reply later setting out how this was done, as it includes two sets of bridged sockets.)

I really can't see why they do this, irrespective of at which end of the cable the termination occurs.
Surely the assumption should be that electric brakes may be required to tow trailers above the specified un-braked maxima, in which case the wire needs to be connected.
In addition, shouldn't all wires that are present be connected if the sockets are available, to ensure compliance with the relevant Australian Standard?

 

[ian059]

I really can't see why they do this, irrespective of at which end of the cable the termination occurs.
Surely the assumption should be that electric brakes may be required to tow trailers above the specified un-braked maxima, in which case the wire needs to be connected.
In addition, shouldn't all wires that are present be connected if the sockets are available, to ensure compliance with the relevant Australian Standard?

Well Barry, I'm one of the ..... "they", or "them"?
I fit towbars and wiring to new Suzukis and Hyundais.
The blue wire as you pointed out is for the electric brakes.
If there are is no electric brake controller fitted to the vehicle, then there is nowhere to connect the blue wire as it runs to the brake controller only.
The black wire is for reversing lights and most, if not all, trailers do not have these fitted, so, nowhere for the black wire to go.

If the customer has requested that a brake controller be fitted then the blue wire will be used, if otherwise, it is not.

I'm not sure what Australian Standard applies or even which would.
The only thing that is standard is the colours, which are consistent across all brands on socket. the seven pin flat socket is all we fit unless otherwise requested and let's face it, why would anyone want the round socket when they get damaged or ripped off so easily (but some people do)? If it is because they have a round plug on their trailer, it is so easy, and cheap,to change it to a flat plug.

Cheers, and a happy new year,
IanC

 

[ian059]

The Tekonsha product literature mentions that many vehicles have a special plug for connecting an electric brake controller that is located near the steering column, for which a cable can be purchased from the vehicle manufacturer.
Cheers, Grum.

Sorry for getting away from your original question Grum.
I fit towbars and wiring to new cars (Suzuki and Hyundai) and have never heard of such a plug.

Perhaps you could email the Tekonsha people for a list of models that supply this plug. Otherwise, just fit according to their supplied wiring diagram.

IanC

 

[Barry]

Happy New Year to you too Ian,

No disrespect intended to those who are clever enough to make car wiring work - whenever I touch it it turns to so much insulated copper spaghetti!

However, for what it is worth, and in no particular order,

... why would anyone want the round socket when they get damaged or ripped off so easily (but some people do)? If it is because they have a round plug on their trailer, it is so easy, and cheap,to change it to a flat plug. ...

I agree totally, I have just replaced the small round plug (yet another variation to complicate the need for adapters!) on my camper trailer with a flat plug, and it was a 5 minute job that even I would've found difficult to botch - just had to remember that the pins connections don't run in numerical sequence. :iconwink:
It is of course possible to knock off the flat plug on the car, if you are silly enough to drag the @rse of an Outback along the Innaminka Rd, due to all available internal and roof volume being occupied with 'stuff'. This accounts for me having become conversant with how my plug was wired. (Of course it would, no doubt, have come off much sooner if it had been one of those big round things! :lol

...I'm not sure what Australian Standard applies or even which would. ...

I don't know much about this, however the 'gumph' on the back of the blister card for the plug I have just fitted boasts, in capitals, that it "Conforms to Australian Standards [sic] AS 2313 and Australian Design Regulation ADR 42/00" Mind you, these can probably be summed up by the allocation of colours (roles) to the respective pins.
For mine, many Australian Standards are not much more than an excuse to express common sense in meaningless code and to charge a hefty fee to purchase the translation!

... If there are is no electric brake controller fitted to the vehicle, then there is nowhere to connect the blue wire as it runs to the brake controller only. The black wire is for reversing lights and most, if not all, trailers do not have these fitted, so, nowhere for the black wire to go. ...

In my view, all wires present should be connected into the car plug then, for example, if a trailer with reversing lights is required to be hauled (and if there weren't the possibility why include the pin and allocate it a colour in the code?) it can be, and the lights will work, without the need to open the car plug to find the problem.

Granted, the blue wire can't be connected to an electric brake controller that isn't present, however there is no reason the cabin end of the wire can't be insulated and tagged, and the wire connected at the plug end, so that there is no need to open up the plug to connect the blue wire at a future date. Especially as if, for example, the wire has been cut short at the plug end, as mine had been, it would be necessary to reduce the length of all the connected wires in order to have the blue one reach.

Every time I have to pull a plug apart to check faults on a 'stray' car or trailer I wonder what is so hard about this.

Surely it much be quicker, easier and cheaper to wire all car plugs with all the available wires in the flat cable. No-one wants to pay the minimum half hour labour to pull the plug apart and alter the wiring. Equally, I'm sure that it isn't aproblem that auto elecs / towbar fitters would want to create or enjoy 'solving'. "Do it once do it properly", everything should then work as intended. (Yes, I still put out a stocking for Santa! )

Have a good first of Jan, and the other 364 as well. :ebiggrin: