Thread: D4 Electric Trailer Brake Wiring

Fitting a Brake Controller is on my future list of things to come. I do hope to fit my Traxide kit this week though. So whilst doing that I want to run the wiring needed for the brake controller. Thinking of Redarc - so to my question

Is there a recommended wire gauge for the brake controller wiring?

All the best

Laurie

Hi all,

well i finally got around to installing my Tow pro today. The install went well, as per Sniegy's instructions without any dramas, until i hooked up the camper. The following is a run down of what works and what doesnt:
- All the trailer lights work - Good
- The remote head lights up without the camper attached - Good
- The Tow pro doesnt recognize that the camper is attached - Bad
- The Disco doesnt recognise the camper is attached, when reverse is selected the sensors still go off - Bad
- When i close any door after getting out, the camper lights flash - Bad
- Green trailer indicator doesnt flash with camper attached - Bad
- The camper brakes dont work - Very bad!

According to the Tow Pro instructions, the indicator light sequence suggests nothing is connected. I wired everything up as per the instructions here:
- Blue Tow pro wire to cut and terminated Brown wire below splice joint
- Red Tow Pro wire into Red car loom wire, below 6 amp diode (with diode stripe facing towards the trailer plug). The only difference here is that i cut the red wire and spliced the diode and Tow Pro red wire in.


What am i missing? Do you guys have any suggestions?

Any suggestions really appreciated.

cheers
Geoff

You don't mention cutting the brown wire Geoff. This is critical.

Scott

Originally Posted by LRD414

You don't mention cutting the brown wire Geoff. This is critical.

Scott

Scott,

yes i did cut the brown wire, below the splice joint. I connected the Blu/black tow prow wire to this and terminated it at the cut splice end.

cheers
Geoff

Howdy Geoff,

Sounds like atleast 2 different issues:

1. D4 not recognising trailer
Does the trailer have LED lights?
Have you installed load resistors across one (or both) of the blinker circuits?
If the above, then yes:
"Green trailer indicator doesnt flash with camper attached - Bad".
"The Disco doesnt recognise the camper is attached, when reverse is selected the sensors still go off - Bad".
"When i close any door after getting out, the camper lights flash - Bad".

2. Tow Pro install
"The remote head lights up without the camper attached - Good". Do you mean when you press the button? It should "breathe".
"The Tow pro doesnt recognize that the camper is attached - Bad". I have an older version of the new Tow Pro and it does not light up without a load on the blue wire ie. sees the electric brakes connected. Before calibration you get alternate flash. After calibration blue/green depending on mode.
From the picture I cannot determine if the wiring is correct.
Do you have a voltmeter? At the Tow Pro check for +12V on Black to ground (White). No voltage between Red and ground, until brake peddle applied (with ignition on).
When you push the Tow Pro button does the trailer brake lights come on?
Is the trailer proven or new? Electric brakes? Drum?

This should start to indicate if your wiring is correct.

Regards,
Gordon

Hi Gordon,

thanks for the quick reply. Below answers in Red

Originally Posted by Nod

Howdy Geoff,

Sounds like atleast 2 different issues:

1. D4 not recognising trailer
Does the trailer have LED lights? YES, however the indicators still flash on the trailer
Have you installed load resistors across one (or both) of the blinker circuits? NO
If the above, then yes:
"Green trailer indicator doesnt flash with camper attached - Bad".
"The Disco doesnt recognise the camper is attached, when reverse is selected the sensors still go off - Bad".
"When i close any door after getting out, the camper lights flash - Bad".

2. Tow Pro install
"The remote head lights up without the camper attached - Good". Do you mean when you press the button? It should "breathe".YES it breathes when i push the button
"The Tow pro doesnt recognize that the camper is attached - Bad". I have an older version of the new Tow Pro and it does not light up without a load on the blue wire ie. sees the electric brakes connected. Before calibration you get alternate flash. After calibration blue/green depending on mode.
From the picture I cannot determine if the wiring is correct I removed the unit from my old 150 Prado and it stayed a solid blue when the camper was connected.
Do you have a voltmeter? At the Tow Pro check for +12V on Black to ground (White). No voltage between Red and ground, until brake peddle applied (with ignition on).
When you push the Tow Pro button does the trailer brake lights come on? NO
Is the trailer proven or new? Electric brakes? Drum?​ Existing camper, no problems in the past

This should start to indicate if your wiring is correct.

Regards,
Gordon

Gordon,

Some pics as requested. Also, whenever i close any door, it illuminates the camper brake lights!
Blue/Black wire into brown


Brown wire below splice cut


Diode wiring

Gordon,

This is the wiring diagram i have used (yes it is crude)



cheers
Geoff