The Haines manual shows a 6 pin trailer plug from 04 to 09.
My 06 outback has a 10 pin trailer plug on the wiring loom. It has all the usual stop/tail/blinker connections plus one with 12v all the time, going to the trailer brake and one with no connection to 12v or earth and shown as "Aux" inside the 7 pin trailer connector. Any clues on where the under dash end of this wire goes. I would like to be able to use it to isolate the trailer battery when the ignition is off. The Subaru harness that came with the tow bar had the corresponding two wires, blue and black, left out of the plug to the loom. Pictures of the same harness, from USA, show the same two wires taped back.images/smilies/confused.gif
Gen 4 trailer plug
- Gannon
- Senior Member
- Posts: 4580
- Joined: Sat Nov 05, 2005 10:00 am
- Location: Bowraville, Mid Nth Coast, NSW
USA trailer wiring is different to ours, they somehow operate all the lights with less wires (from what I have gathered)
I found this in my FSM
The 10 pin plug is as follows
1- Black/blue - Tail lights
2-
3- Brown - Stop
4- Blue/Green - Turn Left
5- Red/Green - Turn Right
6-
7- Black - Ground
8- Black - Ground
Which is slightly different to this diagram for the Impreza
I also found on some site that pin 6 is connected to the rear fog light.
The plug is called "R79" Google search for it and see what you can find
I found this in my FSM
The 10 pin plug is as follows
1- Black/blue - Tail lights
2-
3- Brown - Stop
4- Blue/Green - Turn Left
5- Red/Green - Turn Right
6-
7- Black - Ground
8- Black - Ground
Which is slightly different to this diagram for the Impreza

I also found on some site that pin 6 is connected to the rear fog light.
The plug is called "R79" Google search for it and see what you can find
Current rides: 2016 Mitsubishi Triton GLS & 2004 Forester X
Ongoing Project/Toy: 1987 RX Turbo EA82T, Speeduino ECU, Coil-pack ignition, 440cc Injectors, KONI adjustale front struts, Hybrid L Series/ Liberty AWD 5sp
Past rides: 92 L series turbo converted wagon, 83 Leone GL Sedan, 2004 Liberty GT Sedan & 2001 Outback
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Ongoing Project/Toy: 1987 RX Turbo EA82T, Speeduino ECU, Coil-pack ignition, 440cc Injectors, KONI adjustale front struts, Hybrid L Series/ Liberty AWD 5sp
Past rides: 92 L series turbo converted wagon, 83 Leone GL Sedan, 2004 Liberty GT Sedan & 2001 Outback
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