Towbar Wiring

[Johndouglas]

I've spent the afternoon wiring a 12S socket on the rear end of my new C5 Tourer.   I've got it all done and working except for the reverse lights connection.   Can anyone tell me where there's an easy reach pickup point?

[paul.h]

This post on reversing sensor wiring up may help http://www.citroen-owners-club.co.uk/citroen/topic/15217-after-market-reversing-sensors-help-please/

[Johndouglas]

Thanks for the link Paul.    I've got the job finished now.   I followed Steve's advice by pulling down the headlining and threading the wiring from the o/s wheel arch space, up behind the corner panel and across the roof. I tried the plastic tube method of threading through the tailgate bellows but no way could I get the tubing through. What I did use was a length of 18 gauge galvanized wire bent double. That passed through the bellows fairly easily. With the new reverse wire attached to the loop it finally pulled through the bellows. Then following MrTignale's advice I sorted out the yellow wire in the bundle he mentioned and connected my new wire into it. Big mistake!  My test bulb didn't work but I could hear the central locking clicking.    I took the cover off the tailgate light fitting and started testing for current. On my car the reverse light wire turned out to be red/pink. Once reconnected, and my test bulb lit.

As the new car doesn't have reverse sensors, I got the Gatgetman set off ebay. I prefer having a fixed flange towball on the car, so decided a two sensor kit was less likely to pick up the presence of the towball. It didn't take very long to fit. The rear bumper already has the holes filled with blanks, so it was a simple matter of prising out the plugs and fitting the sensors in the holes. The control box fits behind the wheel arch and behind the removable boot lining panel, alongside the fridge and battery relay.

[paul.h]

You will be wanting to get out with the caravan now. Was the 12 N socket wired with a dedicated kit and how did you run a 12 volt supply for the 12S smart relay ? I have wired a few towbars on our cars and find the wiring takes a lot longer than fitting the bar although I have not tried a dedicated 12N kit.

 

The 2 sensor reversing sensors is a good idea, I find the 2 nearest the towball on our car are hit and miss whether they see the towball - the slightest adjustment of its cover seems to make the difference. I also prefer the fixed flange type so I can have is a bumper protector behind it and a metal tag with a hole for the breakaway cable to pass through.

[Johndouglas]

Having been a caravanner for 50 years, I've fitted a good few towbars over that time. I agree Paul, the wiring takes much longer than the actual towbar fitting. But it hasn't always been so. The first one I ever did to a Mk1 Ford Cortina Estate required some very accurate measurements to be made, followed by the drilling of holes in the chassis members so that strengthening tubes could pass through. Over the years, fitting the bar has become easier as the electrics have become more complex. This time I didn't use a dedicated wiring kit - just a Smart7 relay.   For the supply for the 12S I ran two 17amp wires from the battery across the back of the engine bay, then down to under-floor level.   I'd previously put the two wires into heat-shrink tubing.   I passed them through the plastic conduit covering the fuel lines, up over the fuel tank where they enter the car under the rear seats.   They then pass behind the boot lining to the relay housed behind the pull-off panel where they meet up with the ends of the 7 core grey cable. 
 
Yes - I also prefer a flanged towball with a bumper protector behind it.    And I also prefer two sockets rather than a 13pin type.    Maybe that just a matter of what I've got used to.   The two revering sensors work well with no interference from the towball.   How they will behave when they see the caravan attached is something I'll discover soon.   If they activate with the caravan so close, I'll fit an on/off switch in the supply to the control box. 

[paul.h]

Our latest caravan has a 13 pin plug so I have converted to 13 pin sockets and now prefer them since only one cable and the plug seems to engage better in the car socket - push in and then twist the outer to lock it. Also so far the connectors do not seem to corrode or need nipping together/apart like the old brass pins. I did use an adaptor lead for some time but the cables were too long and had to be wrapped around things to keep off the floor. The car wiring is set up for separate 12N and S with the car 13 pin socket being pre-wired supplied with 2 seven core cables passing through a 2 entry sealing grommet from Towbars Direct who are located in Warrington. On our last C5 I changed the 2 separate sockets for the 13 pin one by simply feeding the 2 cables through its sealing grommet and made the connections.