Using Pin 2 (reverse lights) on a 7 Pin Plug

[pfuller Lurker Find all posts View Profile Close pfuller]

The standard 7-pin plug has Pin 2 for Reverse lights and Pin 5 for brake controller.

I plan on using Pin 2 for an auxiliary source to my caravan.

Does anyone know where Pin 2 - the black wire - terminates in the engine bay? Is it connected to the reverse light circuit (in a 120 Series)?

[pfuller Lurker Find all posts View Profile Close pfuller]

Anyone? Ive been reading their is a loom in the jack compartment, but i'm still unsure where the black wire would run after that...

[mjrandom Out of control poster! Find all posts View Profile Close mjrandom]

How much power? Anything more than a few amps and run a dedicated cable. On 120s and 150s there is a dedicated repeater box plugged into the factory harness. Probably the same with the 90s but that is ancient history now for me. Cut the wire before the box. I suspect that the reverse wire is common to the existing tail lights and cutting it in the engine bay will remove all reversing lights not just the trailer wire.

[carco Advanced Member Find all posts View Profile Close carco]

Yes on our 90 the factory trailer plug harness connects in the left rear jack compartment area.
All the wiring is there, even a couple of indicator relays so you can load up their circuits and not have problems.
But I wouldn't grab a power feed from there and certainly would not cut the reverse signal.
Ours uses all 7-pins of the standard socket which includes reverse and trailer brakes.
For the 12V trailer feed I fitted an Andersen plug on a dedicated circuit running from the batteries.

[pfuller Lurker Find all posts View Profile Close pfuller]

Pin 2 was only going to be used for a 12v feed (less than an amp) to a camera that's at the back of my caravan. I want this on with accessories or ignition and not just when reversing. So I was wondering whether I could change the black wire in the engine bay from the reverse circuit to a accessories/ignition circuit. But are you guys saying that this black wire feeds the cars reverse lights also? In which case I'll run a dedicated wire back to pin2 at the plug.

[adrian5800 Advanced Member Find all posts View Profile Close adrian5800]

Why don't you power the camera from the taillights in the caravan and drive with your lights on?

[carco Advanced Member Find all posts View Profile Close carco]

Think you misunderstood when I said I wouldn't cut the reverse wire.
I wouldn't cut the reverse wire at the engine bay etc, but there's no problem cutting the wire from the factory trailer harness and turning it into a low amp power feed instead of a reverse signal.
There's plenty of moderate amp power feeds in that rear corner so you could cut the wire running from the factory harness plug to the trailer plug, and splice it to one of those feeds.
That won't upset reverse lights etc on the car and will give you the power feed when IGN is on. You could probably even find one that's active with ACC on.

[Clancy Lurker Find all posts View Profile Close Clancy]

IMHO and based on having to have my TVan towed behind another vehicle, it is a PITA to have non-standard wiring at standard sockets. I had to disconnect the electric brakes and the auxillary feed (Reverse lights) out of the plug of the van as the other vehicle had it's factory installed socket incorrectly wired.
It's a little thing I know but keeping the standard plugs and sockets standard is a safer thing and , dare I say it, maintains the standard.
For my reversing sensors and camera on the TVan, I use a separate plug and socket. That way I know that it can't be plugged into another vehicle and have power put into the wrong place.
Friend of mine had their van camera wired into the 5 heavy duty pins of a 12 pin plug on the van and correspondingly to the socket on the car. All was good until the van had to go for repair and another tow vehicle, correctly wired with a 12 pin socket, caused the camera to get 12V up the video line rendering it useless.
Keep it standard I reckon and get a separate plug
Happy days

[carco Advanced Member Find all posts View Profile Close carco]

Totally agree Clancy.
However it would seem the reverse pin has been selected by the caravan industry as a cheap/simple means to get a 12V power feed.

[pfuller Lurker Find all posts View Profile Close pfuller]

Some food for thought..thanks.

I actually have 4 aux feeds i want to run from the van.

1.\ Camera Power (IN)
2.\ Camera Video Feed (OUT)
3.\ An ignition sensor feed from the car to my DC/DC charger (IDC25) (IN)
4.\ An charging indicator from my DC/DC charger to a pilot light in the cabin. (OUT)

I already have a 12-pin plug and anderson plug (for alternator charging) fitted, so i dont really want to be adding an extra plug.

The plan was to include the extra feeds within the 12-pin plug somewhere.

So rethinking the positioning to avoid appliance damage i should choose pin standards (esp for the outbound feeds) that have the least likely chance of having damaging currents being ran to them. (The 5 heavy pins are probably a bad choice since they can handle more current, yet they are less likely used)

So on that basis i'm thinking of using the Earth return for the camera video feed. The Rear Fog (rarely used much in Oz???) for the LED charging indicator. Does that sound reasonable?

Pins 8-12:
1.\ Camera Power - to pin 9(Aux/Battery Lead)
2.\ Camera Video Feed - to pin 10 (Earth Return)
3.\ An ignition sensor feed from the car to my DC/DC charger - (pin 12 Aux)
4.\ An charging indicator from my DC/DC charger to a pilot light in the cabin. (Pin 11 Rear Fog)

[pfuller Lurker Find all posts View Profile Close pfuller]

I found this in Govt Vehicle standards Bulletin:

Because of interchangeability problems that may arise, it is recommended that pin 5 in the 7 pin connectors be used only for service brakes. If auxiliary circuits are required, then the 12-pin type 3 connector would be preferable.

So i'm leaning towards having all my custom wiring in pins 8-12 and having a 7-pin to 7-pin loom for the rare occurrence where another vehicle with a 12pin plug wants to tow my van. (to isolate pins 8-12 and still allow all standard on-road lighting to function.)

[Razorback81 Advanced Member Find all posts View Profile Close Razorback81]

pin 2 on my trailer plug on the 120 was reverse lights in the factory trailer loom
i pulled it out and ran a power wire through pin 2
then ran the reverse wire to my LED in the duel rear wheel carrier

as non of my trailers,boat or caravan have reverse lights it didnt matter to me