Thread: D4 Electric Trailer Brake Wiring

Originally Posted by garrycol

Can I ask where you installed the controlling knob and led??

Thanks

Garry

Dear Garry,
The knob for the controller is to the left of steering column as per Sneigys photos. That part of the install is good and it is not obtrusive. Pity they didnt know how to wire it up. Be ware! Doug

Hi all,
I have had a misunderstanding with LRTech when the D4 was released & the info I have supplied is incorrect, I thought I was told a diode was not required, But have now been instructed to fit a diode to all ETB units fitted to any LR product.
So, a 3 amp diode from any electronic shop costing approx 30c will suffice.
Just tap into the red wire before it exits the l/h/r to the outside, just make sure the kathode end (the side with the stripe on it) faces the Electric Trailer Brake unit.
That will rectify the problem.
I strongly apologize for any problems that may have arisen from this.
If I have fitted your ETB unit, please ring me at work to get this fixed. Takes approximately 5mins to fit & you can be on your way at no charge whatsoever!

I will be at work Mon & Tues this week & then on annual leave until mid
November. If I am not there Simon will rectify the problem.

Cheers

Obviously fitted as a precaution against any reverse current from disconnecting the other end of a coil (eg a relay).

Hi Sniegy, just come in on this thread,as I have been on Holidays.
Could you please be more specific about the diode fit, as I used your circuit details when I fitted my Brake Unit, and wired into the rear left hand wiring loom.
What sort of problems do you think could arise, as a result of not fitting a diode?
Thanks,
Don.

Hi Don,
The fitment of the diode is damn easy, find the red wire that you ran from the Electric trailer brake unit (i would say best location to be in the L/H/R tow hitch storage section) cut this wire in half & fit the diode in between.
The diode has a stripe on one end, this is known as the Kathode & does not let current flow beyond the stripe, this end needs to face towards the electric trailer brake controller end, therefore if it fails it will not let current flow towards the CJB.

The issue may arise if you have a problem with your electric trailer brake unit & it then feeds the problem back into what is called the CJB (Central Junction Box) behind your glovebox, although this is the main fuse block it is also a computer so to speak that controls a lot of talk between nearly all ECU's via various canbus networks. (High speed, Medium Speed)

If this goes down, then you are stuck.

I have altered mine, & would advise that in due course get yours done also.

Cheers

Thanks for that Pete, I will get on to it straight away, as I am getting car, and caravan, ready for a trip up North next week.
I imagine the best way to carry out the job, is to solder in the diode, using a pair of pliers as a heat sink, and then to finish off with a length of heat shrink?

Probably a good idea to include a thin strip of plastic either inside or outside the heatshrink as a brace so that no flexing of the diode's wires can occur. Inside avoids the need to tie the plastic in place.

Hey guys, ive just purchased a RRS and had my dealer install a P3 brake controller for my boat trailer, which uses a Hydrastar electric over hydraulic braking system. The dealer has wired the P3 to my round black 7 pin plug at the back.
However, there is no constant power on that plug. Now he wants to use the constant / ignition power from the white plug and then make up a new harness to combine the output from the two plugs in the RRS to 1 single heavy duty 7 pin to connect my trailer.
My key concern is that the constant power wire that runs to the white plug is not heavy duty enough to handle the 30amp requirement from the hydrastar. Does anyone have a view on this? Also, would this mean i need to connect constant power from the battery to the black plug?
Any help would be appreciated, doing my head in!!