Thread: D4 Electric Trailer Brake Wiring

Thinking about it, LR must think the plug is rated for 30A because of the 30A fuse on the wire going into it.

Narva rate their large 7-pin round as 30A @ 12V per pin, so should be OK.

Hi rlazar, I have answered your PM.

Ok thanks Graeme and sneigy. I spoke to another Autoelec the other day. He's recommending we run a positive direct from the battery via a circuit breaker and also the earth to an anderson plug and have 2 separate plugs for the boat trailer. One for the power ala Anderson plug, and a standard 7-pin flat for the trailer lights and controller (P3). Does this sound about right?

I have that setup, albeit to supply aux power to a van rather than the brake pump.

I decided to put my Electric Brake Controller and Aux Tank gauge on the Small panel on the LHS of the instrument panel.

Time consuming but looks neat and easy to see, also only need to replace a small plastic panel to return the dash to original condition.

Very neat! What did it take to get access to the panel?

Originally Posted by Graeme

Very neat! What did it take to get access to the panel?

Ha, Graeme. Straight to the hard questions, eh.

Ok it was not easy, 1st you need to remove the centre console, then the RHS of the centre dash facia.

Then you need to gently push the LHS of the instrument surround out of the way and I put a tissue under it to stop it scratching the surrounding plastic.

Then it just comes up and out, if you look at the pics you can see 2 "fingers" at the lower edge and another of those stupid tabs with 'fly off into the distance silver clips' Landrover designers seem to love, as used on the rest of the centre console.

Then I removed the inner area behind the bracket on the inner dash assy with my trusty dremmel. After mounting the switches and gauges in the panel it stayed in place even with the 'fly away clip' gone but I used some industrial velcro to keep it in place and prevent any rattles in the years to come.

Simple as that, but I think it looks neater than next to the air vent and headlamp switch which is where ARB wanted to put it.

But the guys in Fyshwick were very helpful and gave me the gauge and the wiring an let me install that bit myself.

I got the ignition switched power from the centre cool box connector under the cup holder.

And I ran a 7 core trailer wire cable down to the back of the cargo area near the tail lamps...(as per Snigeys instuctions a few pages ago). So that has the electic brakes and the Aux tank 'to & from' wires. As well as some spares for another day.

Hi,
Great and interesting read.
I have had a disco 4 for about 6 weeks now.
we tow a 24 foot, 3 tonne van.
Twice the electric brakes have stopped working.
Brake light on the van stop working as well.
The Cars brake light still work though.
This problem can be fixed by turning the car off and starting again.
We thought it might be a short circuit in the brake circuit of the caravan
Put a fuse in the brake light circuit so as to stop the short going to the car but this was not the problem.
Any ideas?

Cheers