Thread: D4 Electric Trailer Brake Wiring

Are the reversing sensors disabled with the van connected? I don't know if the D4 trailer/van brake lights use a dedicated supply from the CJB but if so, the van not being recognised might be a reason for the van brake light failure. The D4 trailer wiring diagram doesn't show the vehicle brake lights being connected to the trailer brake light supply but its quite possible the vehicle brake lights have been omitted because the diagram is focusing on the trailer wiring.

My testing has revealed that a load equating to at least 1 21w globe on each blinker and 2 21w stop light globes are required to provide enough load to ensure that the instrument trailer blinker indicator operates reliably. However the reversing sensors are disabled even though the load is insufficient to cause the instrument indicator to operate, possibly due to just slightly less load caused by more resistance in the wiring than expected. The reversing sensors on my D4 once disabled will not be re-enabled until the ignition is cycled even though the trailer/van has been disconnected, which is similar to your van brake problem. I wouldn't be surprised if a load resistor device solves your vehicle's problems, assuming the brake controller signal splice doesn't have a poor connection to both your brake controller and to the trailer brake supply wire.

A load resistor of 8 ohms on each blinker supply and 2 on the brake supply should provide enough load in conjunction with the LED lights to simulate incandescent globes. The resistors must be able to dissipate energy equivalent to that of a 21W globe so at least 21W but 50W will stay cooler.

Reversing sensors are disabled and as your comment says it requires a ignition cycle to re-enable them. we have only had the Disco for 6 weeks and have been to tassmania and back with the caravan for 5 of those!!
I have never towed another trailer with it so was unaware of the little green trailer light.
interstingly i hooked up the old box trailer this morning and saw the little green light.
so of to the auto elec next week some time (very busy) I will let you know how this goes

on another side issue, does this mean as i have read previously i will need the LR guys to reset my transmission learning??

The gbox ecu adapts constantly. It also has different programming for when it thinks its towing something heavy so your van might not have influenced its normal adaptations that much.

LR have now ordered a Ford branded box that is from all acounts a patch lead ie goes between the car plug and the trailer plug.
i've searched these style of box and found some up to $300 however the one they are proposing is $60 genuine??
any ideas on what the difference is?

Originally Posted by wcody01

the one they are proposing is $60 genuine

That's more like what should be available from a vehicle manufacturer to allow connection of what's become very common-place LED lights, so hopefully it makes everything work properly.

Please keep us all informed what you actually get wcody01

Regards,

Les.

Just to let you all know the box I am waiting for is on back order.will let know when it arrives.

Thought I'd post that I was very impressed with Austals in Brisbane (LR dealer) who fitted both the Redarc remote BC and Autron dual battery display. Very good service. Photos attached (and in my gallery).