Rear light wiring colours ? 2.0hdi

[Martinez]

2001 2.0 hdi 
Seems I’ve made a mistake somewhere in wiring up my rear lights. I’d kept a note and obviously I’ve missed something or got it totally wrong. So I called upon the great God Haynes to assist. I can understand the wiring diagram but not identify which wire is which. Colour codes although provided don’t exist on most wires in any of the circuits, am I missing something ? 
So the basic question is can anyone tell me the colour coding for the nearside rear light cluster ? I’ve managed to get all the lights working so far apart from the reversing light which is permanently on. Also, the air bag light is flashing on the dash, same issue ? Or the usual wiring under the seats ?
My van is a NuVenture Surf Motorhome.  The harness is lengthened by NuVenture to accept the body on the rear. The wiring is spliced to the harness behind the passenger seat. 
Any help greatly appreciated 

[brodfather11]

there should be code numbers printed on the wires , the colour of them dont really match the wiring , its the codes that count.
ie the brown M5 is the earth and is connected to connector 5 on the light unit
the 212 coded wire is the brake light feed and goes to no 2 .
the wire coded VO9D goes to no 3 and is the side light
2333 coded wire goes to the indicator at no 6.
220 goes to no 4 for reversing light

Dont be surprised if none of these numbers I've given match up with yours . check the numbers on the right side light unit  and where they go and except for the indicators you should be able to match them up

[Martinez]

I decided to read the whole of the guidance in the manual and noticed the footnote which confirms everything you say Brodfather. I just hope I can see the codes on the wires as they’ve been cut short. It’s hard to believe that Citroen would devise such a daft idea. Even the Yanks colour code wiring, and most manufacturers follow similar choices in the colours they use. Makes it a lot bloody easier. I’ll have a look tomorrow if I can stay dry

[Martinez]

Just to clarify, do the wires from the r/h side connect to the l/h ?
Think I’m going to have do do a bit more investigating. There’s a loom that goes down behind the seat and another one that runs over to the r/h side. Hopefully it’ll stop raining for long enough tomorrow

[Martinez]

I’ve been through the wiring. Error by me regarding the tail light which is now sorted. But have only one wire remaining marked 202-024-5582-3270.
It’s orange and is + live when ignition is switched on.
Only place this can go from what I can see is to the Reversing light, which puts it permanently on when you start the van. Can’t find any of the numbers on this wire that relate to anything and I’ve got MOT due next week.
Any knowledge of this wire ?

[Martinez]

Still can’t figure this out. I’ve gone back to the connector behind passenger seat. This has 5 wires. 4 of them do what they’re supposed to do leaving the orange wire mentioned earlier. I see from wiring diagram that the reversing light comes from a electronic control unit somewhere, any idea where this is located ?
I’ve had to deal with a leak into passenger footwell and wonder if the leak has caused any damage to electrics ?

[Sol]

Without digging out ServiceBox and not having had an M49, on the later vans the trailer control box which might interact with the rear lights in your case is in the left side rear body cavity I think. Is this orange maybe the trailer bypass relay supply?

Have you checked there is power to the reversing switch on the gearbox when the ignition is on? The colours on the switch will show you what you're looking for inside. The non-live side when ignition is on but not in reverse, will go to the rear lights but without looking at a diagram they could be earth-switched too and have a permanent + but the return controlled by the gearbox switch. That would make sense for an external wire so it can't be shorted, all it can do if it grounds out, is put the reversing lights on permanently....

[Martinez]

Without digging out ServiceBox and not having had an M49, on the later vans the trailer control box which might interact with the rear lights in your case is in the left side rear body cavity I think. Is this orange maybe the trailer bypass relay supply?

Have you checked there is power to the reversing switch on the gearbox when the ignition is on? The colours on the switch will show you what you're looking for inside. The non-live side when ignition is on but not in reverse, will go to the rear lights but without looking at a diagram they could be earth-switched too and have a permanent + but the return controlled by the gearbox switch. That would make sense for an external wire so it can't be shorted, all it can do if it grounds out, is put the reversing lights on permanently....

I was expecting the reversing light to be permanently hot and then the switch on gearbox goes to earth to turn light on. But not on the Berlingo. The switch goes to some sort of electronic control unit which turns the light on.  It may be just a relay, but on the circuit diagram it has the symbol for a transistor. 
I’m afraid I ain’t got no body cavities as it’s a Motorhome body on Bingo chassis. 
Weather is shite hear at moment, but I’ll investigate the wiring behind drivers seat too, circuit diagram shows separate feed to reversing light on that side, but who knows ? If push comes to shove I’ll run a cable to switch on dash and turn it on manually

[Sol]

Aye there's the rub (lol seeing as it's new year) that the motorhome conversion place may have relocated or covered up the control unit.

Might be worth ringing them up or emailing, when everyone opens up next week?

[Martinez]

I think the control unit is behind dash or in engine bay. All they do with conversion is extend the wiring to reach the back. The control unit is called ‘Built-in systems interface’ according to the manual. Could this be the ecu ?
It’s raining again out there today, but if weather picks up I’ll have another mooch