or Login >>         
C4 - DS4 Owners :: Forums :: C4 2011 (B7) DS4 and DS4 CROSSBACK :: The Garage

DIY installation of Towbar Electrics

Home   Forum Rules    Forum Help  Conversion Tools
   
Please Register to enjoy additional Member Benefits
Top Thanked Forum Posts: Today | Week | Month | Year | All time | Most Thanks Given: To member | By user
Author Post
gmerry   
Sun Feb 18 2018, 08:50am
Member No: #11625
Joined: Nov 30 2009
Location: aberdeen
Hi, I'd like to install towbar electrics to a 2012 C4 Hatch.

Looking at the online instructions for the various brands of "car specific" kits, it seems I have to run new wires between the passenger glovebox fusebox and the side of the boot (where the bypass interface will reside).

I've read the instructions for Jaeger, Westphalia, Towsure etc and they all seem to say the same thing.

Can anybody confirm that I will have to remove interior trim, under door kick plates and carpet, to position the new wires?

Many thanks
BigJohnD   
Mon Feb 19 2018, 07:07am

Member No: #82
Joined: Jan 22 2007
Location: Hoylake
Do you have an ignition-switched 12V socket in the boot? That should be able to supply enough power for the lights.
1 User said Thank You to BigJohnD for this Post :
 gmerry (20 Feb 2018 : 12:24)
gmerry   
Tue Feb 20 2018, 12:34pm
Member No: #11625
Joined: Nov 30 2009
Location: aberdeen
Hi BigJohn, thanks for the tip.

I've checked with Ryder Towing by telephone and their bypass relay - Click Here - will work with a switched live feed. In theory, its supposed to be a permanent live. So yes, I will use the lighter socket as feed to the relay.

I'm installing a 13pin socket because my trailers all have 13pin plugs (and the 13pin plugs are miles better in terms of positive contacts etc). With the 13 pin arrangement, I do get the benefit of a reversing light, and using the Ryder bypass, I can even have a fog light cutout if I want that feature.

Looking at the rear lights on the C4 (2012 B7), it seems that all the light sources are individual filaments dedicated to each service (brake, marker, indicator, fog etc) so I'm not expecting any problems splicing into the car wiring.

I looked at the Ryder splicing connections but these seem rather heavy and might strain the wiring. I will remove the insulation, crimp in the new wiring using an open crimp, then make good the insulation using best quality loom tape.

thanks
G

regards
BigJohnD   
Fri Feb 23 2018, 05:13am

Member No: #82
Joined: Jan 22 2007
Location: Hoylake
You do need to be careful when linking in. Any overload will upset the CANBus. There's warning label on the loom to the lights.

Best of luck.
gmerry   
Tue May 08 2018, 07:09am
Member No: #11625
Joined: Nov 30 2009
Location: aberdeen


Hi, an update on the process of fitting towing wiring.

I used a Ryder smart relay, this provides outputs for lighting as per the following list:-

1/ rear taillights (left and rear on a combined circuit)
2/ brake
3/ reverse
4/ left indicator
5/ right indicator
6/ fog
7/ earth

If using a 7pin towing socket, the reverse light function cannot be used as standard unless one want to adopt a highly "bespoke" wiring setup substituting what is normally the separate rear taillights (left and right abd separate on a 7P towing plug). If using a Euro 13pin socket, then no problem.

All the connections to the vehicle lighting can be made on the left side of the vehicle as the C4 has reverse and fog lights on both left and right rear light clusters. The only connection that needs to be made on the right side of the vehicle is one for the right turn indicator. There is a couple of studs mounted on the body, behind the left hand boot trim at the rear base, which is ideal for holding the Ryder smart relay in a clamped secure location.

I found the C4 (B7 2012) rear tail lights to be entirely conventional: no dual purpose filaments that can double as say brake or rear tail light AND no CAN connections whatsoever to the rear tail lights. I found that the vehicle wiring loom connector that plugs into the rear taillight assembly a little loose. Also the wiring was too short to be able to splice in the connectors. The solution was to purchase a new rear taillight connector from this company - Click Here - and then make a loom that tied back into the vehicle wiring, the Ryder smart relay and the new lighting connector.

 

Jump:     Back to top

User Colour Key:
Head Administrator, Administrator, Forum Moderator, Forum Moderator, Premier Member, Technical Expert, New C4 and DS4 Forum Moderators, Member