Towing Electrics Wrong Colour Wires

[jaysams80]

So, I needed to replace my twin electrics.

Hindsight is a wonderful thing but I cut the cable at the plug and upon exposing the wires there are actually 9 wires rather than 7, of which 4 do not match the standard type N plug wiring. Two are for a micro switch and I've found and discounted them. Can someone PLEASE tell me how the others fit? I have earth sleeve colours, purple, 2 yellows...... Surely there must be a wiring diagram out there.

[paul.h]

What car is it ? Is it a 9 core cable and not a 7 core cable to the 12N socket ?

 

I take it by plug you mean the socket at the car and not the plug on the trailer/caravan. If the micro switch is one built into the 12N socket then it is to disconnect the car fog lights when a trailer is connected. Are the wires from a by pass relay or direct from the car wiring ?

 

You might have to trace the wires back in the car to see where they come from or use a meter or bulb to see what puts a 12 volt supply to each one but you may find the purple is an ignition controlled 12 volt supply. Yellow is usually a left indicator and on 12S yellow is the reverse light.

[jaysams80]

Citroen C5. The supply cable to the socket is 9 core. There is indeed a relay from the nearside rear light cluster.

I've had the indicators working and tail lights but the remaining three wires have left me baffled.

[paul.h]

This link to the Caravan Club has details of towbar wiring. http://www.caravanclub.co.uk/media/1022790/towbar-wiring-mo.pdf Likely whoever wired up the towbar has not fully followed normal convention or maybe a vehicle specific kit has been used. It mentions under fog lights if a cut out is used an extra wire is needed, giving 8  but maybe 8 was not available to the installer so used 9 core, or maybe an extra wire is used to provide a cut out for rear parking sensors. Also if the car does not have separate circuits for the left and right tail lights then only one needs to be used so this would leave another spare wire.

 

If the 9 core cable includes the normal 7 core colours and cable diameters, I would be tempted to wire it up to the normal standard and not use the spare wires, just cut them at the ends or tape them back out of the way. This assumes your caravan or trailer is wired up normally.

 

Edit:

Just read on a previous topic your towbar is factory fitted and when connected up the rear parking sensors cut out, so this will be a vehicle specific wiring kit http://www.citroen-owners-club.co.uk/citroen/topic/23809-c5-indicators-flash-fastreverse-sensors-dont-work-after-using-trailer/

[jaysams80]

Thanks paul.h.

Spent some more time under it and didn't manage to get it working so it went to a towbar specialist. Even they struggled to understand how it was wired and yes, it was vehicle specific. Ended up having a relay fitted to bypass parts of the Citroen kit. What a bloody nightmare. They tell me French and Italian brands are buggers for overcomplicating things.