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Grand Picasso wiring colours

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anotherGPowner   
Wed Jul 08 2015, 01:58am
Member No: #41239
Joined: Jul 08 2015
Location: dorset
I am fitting a tow bar to my GP. Mechanically fine but now onto the wiring.
It is not a dedicated wiring kit, just a standard one with a bypass relay.
I have got all the trim off and found the wiring in the left side rear. There are no plugs and boxes, just lots of coloured wires.

Does anyone have the colour scheme for all these wires? They do not match the tow bar electrics colours.
I have got the tail lights and left indicator working but I can't figure out the right indicator.
Dave_Retired.   
Wed Jul 08 2015, 02:11am

Member No: #1
Joined: Aug 07 2006
Location: Northumberland
Yes we have the wiring diagrams - Click Here - but they are not free as we have to pay for them
BigJohnD   
Wed Jul 08 2015, 04:00am

Member No: #82
Joined: Jan 22 2007
Location: Hoylake
Do be careful when cutting into existing wires - any additional current (more than about 10mA which is next to nothing) can cause CANBus problems.

There is also likely to be a warning attached to wiring about these risks.
anotherGPowner   
Wed Jul 08 2015, 09:25am
Member No: #41239
Joined: Jul 08 2015
Location: dorset
BigJohnD - thanks for the warning. I have read plenty of warnings about the CANBus. Surely though this wiring kit is designed to connect to existing wiring via the bypass relay. If I connect the right wires (which I am struggling with, if only I knew what the grey one was!) then I should be OK. I won't touch the twisted pair.
Dave_Retired.   
Wed Jul 08 2015, 12:28pm

Member No: #1
Joined: Aug 07 2006
Location: Northumberland
anotherGPowner wrote ...

I have read plenty of warnings about the CANBus. Surely though this wiring kit is designed to connect to existing wiring via the bypass relay.

Citroen do not recommend the use of By Pass Relays for towing electrics on the Can Bus System, however members have used them for towing camping trailers etc. and there are threads on it on site in the dedicated 'Towing' forum where I have moved your thread to..
1 User said Thank You to Dave_Retired. for this Post :
 anotherGPowner (09 Jul 2015 : 02:19)
anotherGPowner   
Mon Jul 13 2015, 07:45am
Member No: #41239
Joined: Jul 08 2015
Location: dorset
OK I've done it. Just to let anyone else who is interested know, this is what I did.

There was no easy way. I just had to strip out all the trim from both sides in the back and test all the exposed wires with a circuit tester. The colours appear to be just random; on the right hand side both the tail light and the indicator were identical blue wires!

I had to take almost all the trim out. For anyone else trying, start with the little panel above the window and also the top of the arm rest. They are both clipped in so carefully lever off with a screwdriver or something and you might not break any clips. There are only about three screws holding it all on, it's mainly clips.
2 User said Thank You to anotherGPowner for this Post :
 Dave_Retired. (13 Jul 2015 : 13:17) , grousebeater (03 Aug 2015 : 04:33)
LeonP   
Tue Jul 14 2015, 09:05am
Member No: #38558
Joined: Dec 24 2014
Location: Kerry, Wales
Hi,

I fitted a Bypass relay to my 2014 C4P with no problems at all.

I have towed all over the country without any mishaps with the wiring. I also took a feed from the 12v acc plug in the boot to power the fridge.
rogerg   
Fri Jun 12 2020, 10:17am
Member No: #28933
Joined: Jan 14 2013
Location: Kent
I know it was awhile ago but do you remember where you connected the permanent supply to the junction box? I have looked everywhere and found nothing very helpful.
Thanks in advance
 

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