Wiring query.

[lawrence]

While trying to move the tow electrics last night, I found a weird orange box in the access pannel for the rear driver side light cluster. The box has 5 wires going in all marked up. with things like fridge mentioned. where the wires go in. Couldn't get a good look at it. Does anyone know what it is and why its there. If its any use how do I use it. I have been told that there could be wires already wired in to take an extra 12v socket in the boot, it this something to do with that. Sorry about the rubish description but electrics are way aoutside my understanding.

[Bowie69]

It's the wiring/split charge relay for a 12S (the grey one) socket for towing a caravan/camper.

[lawrence]

Oh, didn't realise i had the electrics for a caravan. I only have one socket on the back for the lights for a normal trailer.

[lawrence]

i don't need the wire to run electrics to a caravan as I have no intention to ever tow one. is there any way i can use that wiring then to run other things off it such as a second 12v socket in the boot or a rear spot light.

[Bowie69]

You can fit the electrics without the socket, or maybe someone has removed the grey socket, but left the wiring in place.

I suppose you could use it to run other stuff, but TBH I'd just wire it in a more standard way, run fresh fused, relayed wires from a known power source (the battery and an ignition live if necessary).

Using some electrical for something it wasn't designed for often ends up with your car in flames, and you never know what the PO did to it

[lawrence]

Thanks for the quick response. ill have to find the wires for the 12v socket elseware then.

[MrKev]

It should be wired into a feed specifically installed for the job - you can check this:

There's a fuse, 20A IIRC, in the dashboard fusebox which is the intended feed for the 12S socket, and it would have ended in a female 1/4" receptacle in that location, along with another one for the reversing light, which also appears on a 12S socket.

This feed is a factory installed feed, so I see no problem with running circuits from it for auxillary power in the boot etc, for example:

Additional 12V outlets in the boot. i've used the ISO4165 connectors, much better than normal cigar lighter sockets as they hold the plug in better, but the plugs still go in normal cigar lighter sockets if needed.

sorry I can't work out how to link that picture directly in this thread; maybe a mod can do it?

Kev

[Bowie69]

If it's factory, then fine, but make sure you don't over load it, a spotlight, if wired in will be ~5A, add this to the figures for other connected accessories.

Remember it will only be live when the engine is running/ignition is on, you may find it more useful to have permanently wired sockets instead.

[lawrence]

I only really wanted it to run a spot light, at the back. So i'll have a look into tapping off from the trailer socket then. Does anyone have any pictures of the best way to do this in a simple sep by step sort of way. It would never be used at the same time as the front socket as that is only ever used to charge my phone anyway.

[MrKev]

It's a permanent live - doesn't require the engine to be running, and it's a dedicated circuit, so it will only have what you wire onto it.

If it's factory, then fine, but make sure you don't over load it, a spotlight, if wired in will be ~5A, add this to the figures for other connected accessories.

Remember it will only be live when the engine is running/ignition is on, you may find it more useful to have permanently wired sockets instead.

[lawrence]

One more stupid question, which of the electrical wires would you clever people sugest that I use to power the 12v socket. I guess i will need both live and netural, but which of the wires is best or does it make no real difference. though I best check before i wire it up over the weekend and blow my self up.

[Bowie69]

That sounds rather odd, why have it so that if you leave your caravan connected to the back of your truck without the engine running, it flattens the battery?

At this point I see no reason for having a relay in there now....?

[MrKev]

The 12S gets 3 power feeds: 1 permanent for lights (which may be in your horse box, toilet, caravan, or whatever you're towing) and 2 switched: one for your charging the battery in the trailer / caravan; and one for running your fridge. These switched ones are normally powered though a voltage sensing relay, so that they're only powered when the alternator is charging.

As to the other question:

"which of the electrical wires would you clever people sugest that I use to power the 12v socket. I guess i will need both live and netural, but which of the wires is best or does it make no real difference"

I don't really know what you mean.

Kev

[Bowie69]

Exactly as I understood 12S wiring, but you say 'it is permanent live', well 'it's' not, is it? One is, the one for the trailer running lights?

If it's all fused on the same circuit then find out which one is permanent live and which is ignition/charging live and make your decision to use one of them, For an earth use a ring terminal and a self tapper into the body of the car.

[MrKev]

Ah, ok. I think I've used 'it' too many times in this thread, and lost what the 'it' is referring to.

The 'it' I was referring to is the feed from the dash fuse, 20A, white wire if I remember correctly, which appears in the space at the back near the light cluster. This is a permanent live, and originally terminated in a 1/4" receptacle. It may or may not have been used by the person who installed this 'orange box'.

As you also say, assuming of course that this 'orange box' is a voltage sensing relay (sounds likely, seeing as it's got a wire labelled fridge, but could be anything I suppose) you get a choice of permanent 12V or 12V which is only active when the engine is running.

If lawrence doesn't want the facility provided by a voltage sensing relay, I'd be included to suggest removing it, so as to avoid confusion for him at a later date.

Kev

[Bowie69]

If lawrence doesn't want the facility provided by a voltage sensing relay, I'd be included to suggest removing it, so as to avoid confusion for him at a later date.

Agreed KISS principle

[PaulMc]

The trailer pickup behind the O/S/R tail light is a 9-Way Female connector.

7 Ways are used for the 12N connector, the remaining 2 Ways are used with the Genuine Land Rover 12S Kit, which has Terminals on the ends of the Yellow and Green wires - these plug into the unused positions on the 12N Kit's Male Connector.

The Reverse Lights feed is Green with a Brown trace (GN)

The Auxiliary live is Purple with a Brown trace (PN) and is fed from Fuse 9 (25 Amps) in the engine compartment fuse box.

If you're never going to use a 12S connector, then you could cut the PN wire, behind the RH side trim in the rear, and use this to power your socket/accessories.

For the earths, use the Earth Header's mounting bolt (Grey Connector, with White cap and shiny mounting tab, below the 3rd row seat belt reel) shown without trim fitted, but access through the little grille hatch is possible -

.

[Niamh]

I dug this out from behind the lining on the RHS of the back of my 300TDi-

Anyone got any idea what the connector is or what the green/brown wire is? The previous owner has obviously crimped a butt connector to it for something that never got connected.

Niamh

[PaulMc]

I dug this out from behind the lining on the RHS of the back of my 300TDi-

Anyone got any idea what the connector is or what the green/brown wire is? The previous owner has obviously crimped a butt connector to it for something that never got connected.

Niamh

That's the 12N Towing Connector pickup (same as a Range Rover Classic)

The Green/Brown cable is a Reverse Lights feed, there should also be a Purple wire, which is a permanent fused live, behind there.

The connector is a RISTS 7-way splashproof connector, which can be bought from Autosparks -

http://www.autosparks.co.uk/product_info.php?products_id=1761

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[MrKev]

Indeed - I have the above, and I agree with the colouring. My memory was playing tricks on me when I said it was White.

PaulMc - is that the connector block in a Disco II by chance? The original post's signature claims a 1995 300tdi Discovery...

Kev

[Niamh]

The Green/Brown cable is a Reverse Lights feed, there should also be a Purple wire, which is a permanent fused live, behind there.

No switched fused live?

Any idea which fuse the purple goes to? Is necessary I could always relay it.

Niamh

[PaulMc]

PaulMc - is that the connector block in a Disco II by chance? The original post's signature claims a 1995 300tdi Discovery...

Yes, it is - I don't know where I read it as Discovery II

The Discovery 1 has the 7-ways for 12N Towing on that RISTS connector and the Reverse and Auxiliary Lives on individual wires (terminated in female bullets)

Their location is inside the car, rather than behind the O/S/R Light, but the wire colours are the same.

.

[PaulMc]

No switched fused live?

Any idea which fuse the purple goes to? Is necessary I could always relay it.

Niamh

No, it's a permanent fused live, on a Purple/Brown wire.

It's fed from Fuse 6 (20 Amp) in Satellite Fuse Box 2 (under the facia), which (according to RAVE) also powers the Radio, Clock, Alarm, Indicator Light, Interior Lights & Loadspace Lights.

.

[Range Rover Blues]

My older RRC has the round black connector for the trailer wiring but my newer one had a rectangular white socket with blades inside it. I just paxked it with heavy grease and I don't off-road that car.

I noticed some, can I say confusion? as to what the various power supplies to the trailer sockets are. There is no definitely correct answer because the 12N/12S has changed over the years, I'm not as familiar with the 13pin continental system but I belive it's going to take over here in time. Explorer group already fit their new 'vans with it.

Years ago when 12 volt lihgts first appearedin caravans the car was left connected and the lights ran from it. People quickly realised this was dum and added batteries to the caravan in parallel with the car, so that when the car was disconnected the lights stayed on.

This started life as the blue wire on the 12n. By the late 70s this had been displaced by the fog lights.

As caravan got more sophisticated they drew more power and the second (blue or red) connection to the 12s was added. This drew power only when the ignition was on for stuff like a fridge.

By the 90s caravans had big fridges that needed their own power suply and their own earth, the black wire on 12S and the red wire are dedicated to the fridge.

Soon after the blue wire was dropped, this had been soley to charge the battery and in order to lower the current drawn by the 'van what happens now is that when the red wire become live a relay switched power from the green to the blue. My caravan is wired up with a 5-core cable on the 12S not a 7-core.

Anyway, to ensure mine are compatible with as many trailers/caravans as possible I wire the green wire via a fuse to the battery, the red and blue via separate fuses and a voltage sensitive relay (on my LSE it's an alternator switched relay) using 17 amp or bigger cable for each.

Also the white and black wires need to be earthed and to different earth points on the towcar, this is important.

Some voltage sensing relay kits use 1 wire to supply the relay which then splits to the 3 wires, green red and blue. Not ideal in my mind as the supply should potetnially be over 30 amps (the current limit on any single pin is 16 amps and there are only 2 earth pins) so I use 2 sensing relays, one ofr the green/blue and the other for red.

[PaulMc]

Some voltage sensing relay kits use 1 wire to supply the relay which then splits to the 3 wires, green red and blue. Not ideal in my mind as the supply should potetnially be over 30 amps (the current limit on any single pin is 16 amps and there are only 2 earth pins) so I use 2 sensing relays, one ofr the green/blue and the other for red.

The Genuine Land Rover 12S 'Split Charge' Kit, uses a Voltage Sensitive Switch PRC4427 to switch 2 x 30 Amp Relays, one for the Red wire and one for the Blue wire.

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