Thread: D4 Electric Trailer Brake Wiring

The thought process behind the Anderson plug was that the standard wiring wouldn't be able to handle the current. The brake guys were going to do the Anderson wiring a whole lot thicker and do the van to match. Perhaps not necessary.

Hi Sniegy, yes it was a late night typo, I tried to go back in the day after but I was out side of the edit window, it is in the red wire as per the instructions.


I will try to contact the site administrator and fix it, thanks.


PeterJ

[Just a quick question Peter,
You say the Diode in the Blue wire?
Just wanting to confirm that this is a typo & you haven't installed the Diode in the blue wire as it SHOULD be the RED wire as per install instructions.

Cheers ]


Hi Sniegy, yes it was a late night typo, I tried to go back in the day after but I was out side of the edit window, it is in the red wire as per the instructions.
(Mucked up putting your quote is as well, still learning I am afraid)

I will try to contact the site administrator and fix it, thanks.


PeterJ

So just following on with the 12 pin conversion, if the camper trailer has LED's, presumably, you could run a 'plug in' load resistor on the 7 pin socket (wired across an indicator terminal) and use the new 12 pin for the camper right? That would be simple if you can. Can't see why not. Thoughts?

Originally Posted by sniegy

Epic, With using a 12 Pin plug is there really a need for an Anderson plug?
Not sure of your requirements but being in contact with a lot of trailer manufacturers lately a lot seem to be going this way, just using a 12 Pin plug which has room in the top 5 pins to be able to use this an Anderson plug replacement. One plug that does everything.

Cheers.

Thank you to all the contributors on this post. I've just spent the best part of two hours trying to get my head round this subject. My husband is not into computers, so I do the trawling on the forum for any relevant info, so please understand my lack of too much technical knowledge.
Here's a quick run down of our problem.
I bought my MY11 D4 TDV6 a year ago and it came already fitted with a P3 EBC which worked through a 7 pin flat trailer plug. We tow a camper trailer, weighing about 1200kg full loaded. The EBC worked fine, as did all the trailer lights (LED's).
About 2 months ago, in preparation for a 4 month trip to the Kimberley, we replaced the electric brakes on the trailer. Straight swap - whole unit off, whole unit on.
We also recently decided to replace the 7 pin with a 12 pin plug so we could run the fridge in the camper from just the one plug, rather than the Anderson plug that was there before.
The auto-elec we got to do the job said it was a relatively easy swap. After getting it home, we tried the camper on the car and found the EBC didn't recognise the trailer. Back to the auto-elec who had made a mistake with wiring the number 5 pin. All fixed and home again.
Last weekend, we went to give it a test drive, and the controller recognises the camper, but the brakes to the camper don't come on when the brake pedal is used. The camper brakes can be put on by using the manual override lever, but even when adjusted fully up, don't slow the camper much with the pedal.
Just to check it wasn't the unit, we took the remote head of the P3 out and swapped it with the Tekonsha unit in my husband's Defender. My unit worked fine in the Defender, and his unit did the same thing in the D4.
Rang the auto-elec who is coming on Saturday to have another look, but says he can't think what it would be!
That trip to the Kimberley is now only 10 days away and I'm starting to get edgy.
Does anyone have any ideas what it could be - hopefully something simple like a fuse or a relay? I'm going to print out all 27 pages of this thread to show the auto-elec (he'll love that!).

G'Day 'Sniegy', 'Drivesafe', All,

Being about to start on the well trodden route of hooking up a jayco caravan to a D4 I find myself with the often discussed 'to 12pin flat or no to 12 pin flat' decision.


From what Jayco tells me the maximum current draw re the fridge on pin 9 (ignition) would be about 9-10 amps going directly to the fridge while pin 2 (permanent) goes to the battery in the van after it has been thru power management unit.


Noting that there are a multitude of threads which I have tried to check out before posting, I have a couple questions that I hope you might be able to answer regarding to the replacement of the white 12S plug with a 12pin flat
plug.


1. How would the 12 pin (replacing the white 12S) be connected up? Would the feeds for the indicator, break light wires etc simply get tapped from the rear of the black 12N plug?

2. Could the +ve and -ve wires from a Traxide rear 'Anderson' plug be fed into the rear of a standard 12 pin plug (pin 4 - permanent 12V) - in order to enable battery charging via charger/solar using a separate 12pin plug with just the permanent 12V and ground pins present?

3. And most importantly of all, would you consider the replacement of the white 12S with a 12pin to be a DIY job? If not, could you provide an estimate of the likely cost to have this done? Is this something your place does Sniegy?


Thanks a mil,
RickO

Hi Magic,

The P3 has some really handy diagnostics you may not have come across yet. Access them by pressing the bottom right hand button (looks like and open book) and then arrow down to help, select that with OK (the book button), arrow down again to troubleshooting and select that with OK (the book button).
You can now arrow through 4 readings which can help diagnose the problems. ie.
1. Battery Voltage
2. stop light voltage (what you get to trigger the thing from the brake light)
3. Output voltage
4. Output Current (this should be very useful)

The reading at 2 (stop light voltage) should be around 12V when you either manually operate EBC or put foot on the brake. Manually operated the P3 puts the 12V on itself, foot on brake its expecting the 12V to come from the brake light circuit. If the trailer brake lights come on then look where the red wire from the P3 is connected as it should be picking this up.( maybe via a diode ?). If the trailer brake lights don't come on then you will need to determine why and this will probably resolve issue with EBC triggering as well.
Info on P3 diagnostics is down around page 22 on this post.

Regards
Gerry

Magic,
With all the work that the Auto sparky has done it could be anything.
He may have done a great job & it may be the wiring of the new brakes.

It is hard to comment without physically investigating the work.

Just show the Auto sparky how it is supposed to be done via the first page & if he has followed this all should be fine.

Also do not connect the brake light pick up from under the dash. It should be done from the rear on the trailer wiring harness itself...Oh & also to include the diode.

Cheers & good luck.