Thread: D4 Electric Trailer Brake Wiring

FETs are indeed used. FETs are a 1-way switch normally with an inbuilt reverse current protection diode. Reverse breakdown voltage is typically 100V. They are often used to switch on a circuit from multiple sources, with each one unaffected by any other.

Have recently picked up MY10 Disco TDV6 3.0. Previous owner had setup for towing including;
- Prodigy Brake Controller
- aux Power via wiring and Anderson Plug routed to trailer plug
- 2 x coax leads routed from under brake pedal to rear trailer plug. I suspect these were camera on vehicle rear (viewing tow hitch) and another at caravan rear.

I have tested wiring to ensure all setup ready to tow, and have confirmed all good as per Australian wiring except for reversing lamp via Pin#2 of Black 12-N. No voltage when vehicle is running and reverse selected. Pin#1 of White 12-S provides 13v when reverse selected.

My question is could this be a mod rather than a fault. Looks to me like vehicle was set up for breakaway. Is there any reason reverse via Black 12-N would be removed / replaced? Should I be looking for a fault or a mod?

Cheers

Originally Posted by Fishoon

Pin#1 of White 12-S provides 13v when reverse selected.

Factory standard wiring.

Quick pic of my TowPro install.
Head unit (dial) has replaced one of the 12v socket in centre console, no holes drilled in the car, easy install with the console out, easy to revert to factory.
Very easy and instinctive to reach in this location, and as recommend by the getabout training guys as I understand.
Haven't found the control box yet (have been told to stop pulling new car apart!), but it's up in behind the nav somewhere.
Impressed with seamless operation of the TowPro itself, once calibrated with trailer attached.

Afternoon folks. Just bought an MY14 SDV6 and need to fit a brake controller to tow the van. I was going to get it fitted by an auto electrician but after reading these pages (a few times) it looks to be no worse than fitting the controller to my D1. So after considering what I've read here this is what I've decided on, let me know if you see any glaring errors
I'm going to use a Redarc Tow Pro, wired up as per instructions here, with the remote mounted on the light switch panel. At the back I'm going to stick with the original black 7 pin socket (I figure its easier swapping plugs on trailers than car wiring). That will cover lights and brakes.
For the ancillaries I thought Id use the ignition activated 12 V supply on the white socket. I've ordered a couple of white plug's, so one can go on the van for this and the other can be set up for battery charging.


Now a couple of questions;
On the black plug, is Pin 2 wired up for reversing lights (Aust), fog lights (UK), or is it a 12v auxillary feed, and if so, is it constant or ignition activated?


Secondly, on the white socket, is the earth (or neg) connected to pin 3 or pin 7, or both?


Finally, our car is a Dec 13 build, can anyone confirm the splice I cut into is in the rear panel accessed from the load space and not under the tail light?


Cheers Mossy








Cheers Mossy

Hi Mossy,
Refer below for answers.

Originally Posted by Mossy

Afternoon folks. Just bought an MY14 SDV6 and need to fit a brake controller to tow the van. I was going to get it fitted by an auto electrician but after reading these pages (a few times) it looks to be no worse than fitting the controller to my D1. So after considering what I've read here this is what I've decided on, let me know if you see any glaring errors
I'm going to use a Redarc Tow Pro, wired up as per instructions here, with the remote mounted on the light switch panel. At the back I'm going to stick with the original black 7 pin socket (I figure its easier swapping plugs on trailers than car wiring). That will cover lights and brakes.
For the ancillaries I thought Id use the ignition activated 12 V supply on the white socket. I've ordered a couple of white plug's, so one can go on the van for this and the other can be set up for battery charging.


Now a couple of questions;
On the black plug, is Pin 2 wired up for reversing lights (Aust), fog lights (UK), or is it a 12v auxillary feed, and if so, is it constant or ignition activated?
**Pin 2 on the Black plug is wired for the UK & Fog lights.
**It can be easily changed tho' from the inside of the l/h/r cargo area.

Secondly, on the white socket, is the earth (or neg) connected to pin 3 or pin 7, or both?
**Both.

Finally, our car is a Dec 13 build, can anyone confirm the splice I cut into is in the rear panel accessed from the load space and not under the tail light?
**Inside the l/h/r cargo area, not below the tail light like mine &/or early builds.

Cheers Mossy

Cheers.

Thanks Sniegy, will have a go this coming weekend.

Sniegy
Just taken delivery of MY 2015 SDV6 Discovery and propose to have a Redarc Tow Pro fitted next week by an auto elec with LR Disco experience.
I have already found out that my trailer connection does not need a shunt/tow connect unit now to ensure comparability with the LED's on our caravan - not sure if LR have just addressed this problem with the 2015 models.
So I was wondering if you were aware if anything has changed regarding wiring of an EBC in the 2015 spec Disco, such as plug and play.
I am installing a Traxide aux battery system next week and was planning to run blue wire for EBC at the same time (as suggested and supplied by TIm at Traxide), but after enquiring with a local installer it appears I need to run 2 wires as per your earlier posts.
Would appreciate your comments.