[Rowant]

I have just installed a towbar on my hse and, rather than spend approx NZ$100 for a complete wiring harness, I bought a pack of pin terminals and a plug and made my own - $12.50.
I was told specifically not to just hook into the wiring loom as an auto sparky would but use the plug - other wise I could have ´fault´ problems. The factory wiring loom has 7 pins - for L and R indicators, brake, earth and TWO tail lights. I am under the impression that both tail light pins must be used so I just put a 2 into 1 join and everything works ok - I even get a trailer symbol flashing on the dashboard in time with the indicators. And I have no faults appearing.
BUT there is one loom plug terminal unused and I have no idea what it is for - it is red with an orange tracer. I have checked and it does not seem to be related to the reversing light circuit. Maybe for electric trailer brakes?

Can anybody cast any light on what this extra wire is for?

Cheers

 

[leftlanetruckin]

I had a look at my alldata account for my 98 NAS, and I cannot see the wire you are talking about!

Martin

 

[Rowant]

The wire in question is one of the seven that make up the wiring loom trailer plug that is to be found inside the panel behind the right hand tail light assembly. It comes like that from the factory.

Rowan

 

[leftlanetruckin]

Per Alldata...

Accommodation within the system has been made for the addition of a trailer lighting system to consist of 2 side lamps, 2 fog lamps, 2 reverse lamps, 2 brake lamps, 1 LH indicator and 1 RH indicator. In addition to these loads, there is also a provision for a 10 amp battery feed to the trailer.

So I am wondering if the wire in question is the battery feed provision? It may not be live at the moment, but maybe that is it?
If I was home I could look at the FSM too, but I am currently @2000 miles from there....
Martin

 

[Rowant]

Maybe the Japanese spec model has different wiring - mine is ex-Japan.
I have rechecked my wiring and mine has no provision for reversing lamps or fog lamps - and I assume that your term ´side lamps´ refers to tail lights ( wired into the park light circuit).
When I wired mine up I checked every terminal on the loom plug with both a volt meter and a probe (double checking) and I only have what I mentioned earlier.

I considered that one of the two tail light wires might have been for a rear fog lamp but that would mean that my trailer would have a super-bright (21w+) extra red light blinding following traffic. Then again an ´international´ model might need it in some countries - it seems to be part of the tail light system.

I reckon that I have things sorted as they are so, unless I have really screwed up, I will just use it and not worry too much about this seventh wire.

Thanks anyway

 

[John W]

Most of the standard trailer sockets usually have an pin for a fridge( ie towing a caravan).I dont know if the RR have included this in their wiring or not though. :think:

 

[munichp38a]

I considered that one of the two tail light wires might have been for a rear fog lamp but that would mean that my trailer would have a super-bright (21w+) extra red light blinding following traffic. Then again an ´international´ model might need it in some countries - it seems to be part of the tail light system.

Although I haven't installed the trailer wiring myself I can confirm that at least in Germany a rear fog lamp is legally required on trailers.

Sigi

 

[leftlanetruckin]

There is indeed a different wiring diagram for Japan market rigs ("Japan only" on a diagram)
Dont have time to look now, but will try top check it out later this evening.

Martin

 

[leftlanetruckin]

Most of the standard trailer sockets usually have an pin for a fridge( ie towing a caravan).I dont know if the RR have included this in their wiring or not though. :think:

Read a previous post of mine, and you will have the answer.
Here it is anyways.....

Accommodation within the system has been made for the addition of a trailer lighting system to consist of 2 side lamps, 2 fog lamps, 2 reverse lamps, 2 brake lamps, 1 LH indicator and 1 RH indicator. In addition to these loads, there is also a provision for a 10 amp battery feed to the trailer.

Not solely for a fridge per say, but a 10 amp feed to the trailer non the less.

Martin

 

[John W]

Most of the standard trailer sockets usually have an pin for a fridge( ie towing a caravan).I dont know if the RR have included this in their wiring or not though. :think:

Read a previous post of mine, and you will have the answer.
Here it is anyways.....

Accommodation within the system has been made for the addition of a trailer lighting system to consist of 2 side lamps, 2 fog lamps, 2 reverse lamps, 2 brake lamps, 1 LH indicator and 1 RH indicator. In addition to these loads, there is also a provision for a 10 amp battery feed to the trailer.

Not solely for a fridge per say, but a 10 amp feed to the trailer non the less.

Martin

Correct Martin,But I have seen on a pin out diagram the Battery feed specifically labelled "Fridge" :dance:

 

[leftlanetruckin]

John, I got ye mate. My Alldata just lists it as I posted above, and cannot get to my FSM right now.
Here is the Japan diagram, although all I am seeing is the CD changer being fed from the same wire as the non Japan model......
[attachment=0:ys60nt36]rr.gif[/attachment:ys60nt36]

Martin

 

[paul.adshead]

Japanese models have the same trailer wiring as all the other P38s.

The 'Japan Only' tag in that RAVE diagram, is, as you say, just saying that the CD Changer is powered from a feed also going to the trailer, on Japanese models. NOTE however, that this connector is termed "Trailer Auxillary Socket". The P38 was (as are most European vehicles), designed to use TWO seven-pin trailer connectors - 'standard' and 'auxillary'. The standard connector does:
- left indicator
- right indicator
- brake/stop
- side lights
- rear-fog lights
- earth
- spare
The auxillary connector does:
- 12v permanent feed
- 12v switched feed (often termed "Fridge")
- reverse lights
- earth
- & a few spares

I've just dug out the diagram I made 3-4 years ago:

 RR  Loom                            NZ/Aus standard
Pin Colour        Purpose           7-core wire colour 
------------------------------------------------------
1   big black     earth             white
2   red/black     side trailer      brown
3   green/yellow  right turn        green
4   green/red     left turn         yellow
5   red/yellow    rear fog          blue
6   (vacant)      -                 -
7   green/purple  stop              red
8   red/white     side trailer &    (use pin 2 instead)
                  car rear RH side

Apologies for the 'code' window, but it's the only way to get the words to line up.

@Rowant > I would NOT tie pins 2 and 8 togethor - you will 'confuse' the BECM and it is un-necessary. Confusing the BECM is not a game I would entertain...

Re the 'auxillary' connector, then you will find this connector in the same location but on the left hand side. The auxillary connector has 3-4 pins on these (- earth; reverse; 12v supply (can't remember if it is switched/permanent/both).

 

[Claude]

To go back to the original question, I think you may have misread the colours. Paul has listed the colours in his last post which are the same as in my hardcopy version of LRL0006ENG (the Electrical Troubleshooting Manual) and the same as on my vehicle. These are the wire colours at the multiplug C330 located behind the small access panel. There is no Red with orange tracer but there is a red with yellow tracer which is the fog light.

Also, as Paul has pointed out, the references to Japan and non-Japan wiring are not associated with the socket which you are connecting up to (referred to as 'X286 Trailer Main Socket') but with the other socket (X172 Trailer Auxillary Socket) which is the one thats used for a caravan and has the fridge and 10amp feeds etc which others have referred to .

 

[Rowant]

Thanks all and sorry for not replying earlier - work get in the way sometimes.
I have unplugged the extra tail light wire and everything is still working ok.

I don´t have any access panel behind the left tail to get to any plugs that are there but that doesn´t matter anyway.

Another thing that had me a little confused for a time was the reference to ´side lights´ until I realised that it refered to tail lights. Side lights have a different meaning over here.

Thanks for all the help. Cheers

 

[paul.adshead]

I have unplugged the extra tail light wire and everything is still working ok.

That's good - no point in confusing/damaging the BECM.

I don´t have any access panel behind the left tail to get to any plugs that are there but that doesn´t matter anyway.

I guess you have the sub-woofer fitted to the left hand side? There are four 'locks' securing each corner of the subwoofer cover - turn each lock a quarter turn anticlockwise and the cover will come off. Behind this cover, is another access panel, in identical position to the right hand side. Put you hand in the opening and reach forwards about 6" - the plug on this side is taped to the loom that feeds the rear-left lights.

Another thing that had me a little confused for a time was the reference to ´side lights´ until I realised that it refered to tail lights. Side lights have a different meaning over here.

Side/tail, all the same. The lights that show the corners of the vehicle.