Tow bar electrics advice please

[fastjet]

Could I ask for advice on towbar electrics please?
The connector picutured below looks as though it is for a dedicated wiring kit, is that correct? If so does it need to be enabled via Lexa 3 as there does not appear to be any power to it. I went through all the lighting options with a multi meter but none of the pins were live when the lights were on.

Can you fit a standard bypass relay to a MK1 C5 (2004)?
Also, is there dedicated point to take a 12volt supply from?

Thanks

[GiveMeABreak]

The recommended official towbar electrics have an ECU that interfaces with the C5s systems - specifically enabling a specific mode for the ESP system to compensate for towing (I know oyur specific vehicle is without ESP). It may also, when connected (towing) automatically disable parking assistance if fitted. So there are advantages to these systems.

The correct kit for your car is part number 9428 76 (pic below) and is currently £95 incl. VAT from Citroen. Picture below for description of content:

Just be aware that the C5 is a fully multiplexed CAN vehicle so be careful with the wiring generally as you may get unexpected results.

Click to Zoom

[fastjet]

Thanks Marc you are a star.

[JohnD]

Can you fit a standard bypass relay to a MK1 C5 (2004)?
Also, is there dedicated point to take a 12volt supply from?

I've wired both my C5s using bypass relays. The first a 2005 model and then my 2010 -X7. In both cases I used a TEB7AS. I took the 12 volt supply for fridge and permanent live from the car battery (through fuses), via two 17amp cables to the boot area.

[sparksie]

Well, not having done a modern Citroen, I can only offer general advice.
As a rule, anything multiplexed should only use manufacturer approved, or similarly specced aftermarket kit.
Having said that, there are going to be times when that's just not possible, soo...
With care, it's usually possible to tap into the light circuits and feed bypass relays from them.
Some are more sensitive than others, so you may find you have to use ultra low draw reed type relays and use them to trigger normal relays.
When I started playing around with this, I initially thought I'd have to use a transistorised relay, but so far it's not been necessary.
If the genuine towing relay kit is available at an affordable price, it's definitely the way to go.
The DIY option is more susceptible to failure caused by wear in moving parts, or damage from clumsy loading of luggage, or simply dampness.
Also, the cost of relays, connectors, circuit boards/boxes and such can quickly mount up, especially if paying someone else to assemble them.
Hope that helps

[fastjet]

Well, it is going to take 3 weeks for my local Citroen dealer to supply a tow bar electrics kit.

[fastjet]

Hi.
I have managed to get a Citroen 13 pin wiring kit for my car, but there is now wiring diagram with it.
Can anyone supply a list of wire colours matched to function? ie lights, rh indicator and so on.
Thanks

[Paul-R]

This any good (middle of the page)?

http://www.malcolms.ie/towbars/informat ... g-diagrams

[fastjet]

Thanks Paul R for your post.
The problem is that the Citroen wiring kit wire colours do not match. For example it has two wire coloured yellow and green which could indicate that they are both earth wires.
Another example is a purple wire which I am struggling to find its function in the circuit.

[Paul-R]

With the wiring kit (if new) there should be a set of instructions giving the colours and where they go. Yes, green/yellow are earths (more than one, could be two or even three)

Incidentally, I'm surprised that you've got a 13 pin kit for the Mk1. Normally they used the older 7 pin sockets.

[Paul-R]

This is from the instructions that came with my Citroen electrics kit for the X7. Any help?

[fastjet]

Thanks Paul R the colour codes look very close I will go and check.

What are C and D used for?

[Pug_XUD_KeenAmateur]

3 weeks for my local Citroen dealer to supply a tow bar electrics kit.

Cor strewth, they must be really keen to have your custom (sic). Take a look at these listings (type in the item numbers to ebay.co.uk), see if any of them are what you need.

[Paul-R]

From memory (the X7 is in the UK - I am not) C & D is/are the microswitch and wires that detect when a plug is inserted into the socket.

When the BSI is set up to recognise the wiring is present it will then alter (amongst other things) the braking characteristics for the ABS when towing. I doubt very much that the Mk1 would have the capability for this.

[fastjet]

Hi Paul R.
Thanks for the reply. I have now worked out most of the wiring, your wiring diagram was very useful. Some of the wiring colours matched some didn't, but enough did to provide a good starting point. My mk1 has the fog light switch, wires C&D, the O + T threw me when I first read it. I am now working on the permanent live and the switched lives. Thanks for your input.