Brake Controller Trigger Wire?

[cdsvt]

I've read tons of threads here and the violet/orange wire in the trailer controller bundle under the second row passenger seat seems to have been unreliable. Is anything better with the most recent software updates?

Fwiw, I took delivery in July 2025 with the latest software updates.

I'm working on installing a Redarc TowPro Elite (which I've done on several other vehicles- all Toyotas), and found a super useful thread for all wires except the brake signal (Redarc blue) wire.

Redarc wire color - purpose - Vehicle wire color
black - 12v constant - yellow/red
white - ground - black
blue - control - grey
red - signal - violet/orange

Any up to date guidance would be greatly appreciated!

Thanks.

 

[TheDocAUS]

You will need some US input, because I believe the REDARC is wired slightly different in the US to Australia.

 

[Itsdchz]

This is the thread I used to install mine

Thread 'NA Trailer Brake Controller Install'

Mar 16, 2024

Just finished installing and testing a trailer brake controller on our NA Grenadier.

Went with the Redarc EBRH-ACCV3-NA Tow-Pro Elite Electric Brake Controller; as suggested by Mark @ Redarc. This is the same unit we had on our Defender.

I also needed to order a longer remote wire to move the remote head to the front dash area for mounting. The extension hasn’t arrived yet, so for now the remote is strung to sit between the drivers seat and the center console: RHWK-004 13ft Tow-Pro Elite Remote Head Wiring Kit.

On to the wiring…..

1. Under the back seat, on...

• ScottnAZ
• brake controller brake wiring install towing trailer trailer brakes wiring
• Replies: 239
• Forum: Wheels, Tires, Brakes, TC, TPMS, Towing

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[TheDocAUS]

Thanks I added that link over in the Resource section.

 

[cdsvt]

I used that link but the trigger wire isn't ideal. It is an option, but if Ineos fixed the software driving the factory brake trigger wire that would be a cleaner solution.

 

[Itsdchz]

I used that link but the trigger wire isn't ideal. It is an option, but if Ineos fixed the software driving the factory brake trigger wire that would be a cleaner solution.

Only relevant IF they fix. Could be either a software or hardware issue. Hard to tell….. The running of a line to the actual wire, and using the diode, is the best bet for now. Betting on waiting isn’t worth it IMHO.

 

[cdsvt]

Only relevant IF they fix. Could be either a software or hardware issue. Hard to tell….. The running of a line to the actual wire, and using the diode, is the best bet for now. Betting on waiting isn’t worth it IMHO.

That is what I'm trying to ask: DID they fix the brake signal reliability in the violet/orange wire in the latest software update?

 

[LeeroyJ]

That is what I'm trying to ask: DID they fix the brake signal reliability in the violet/orange wire in the latest software update?

I haven't seen anything that said they did in the update notes. Try asking a dealer?

 

[Itsdchz]

That is what I'm trying to ask: DID they fix the brake signal reliability in the violet/orange wire in the latest software update?

Dealer went over release notes for my 24.1 update and was not present.
I honestly do not think this is software….

 

[cdsvt]

I ordered the Redarc diode.

This vehicle is delivered like a not quite finished project. There's always something more to buy to fix some deficiency that Ineos left for the consumer to deal with.

 

[cdsvt]

So I've wired the redarc control box in as described in the linked thread:

Redarc wire color - purpose - Vehicle wire color
black - 12v constant - yellow/red
white - ground - black
blue - control - grey

Can anyone tell me what color wire I can find in the rear quarterpanel that is attached to that grey wire? I don't see a grey wire in the bundle to the TCM plug. I need to wire whatever wire this is in to the blue wire on my 7 pin trailer plug. Alternatively, I could run a wire directly from the redarc harness to the 7 pin trailer plug, but I'd rather use the existing wiring if possible.

Does anyone have a handy brake signal wire that I can also use? I need a wire that tells me that the brakes have been applied. This will go to the red wire (via the Redarc diode) on the Redarc brake controller.

This is a US delivery 2024 grenadier.

 

[Itsdchz]

So I've wired the redarc control box in as described in the linked thread:

Redarc wire color - purpose - Vehicle wire color
black - 12v constant - yellow/red
white - ground - black
blue - control - grey

Can anyone tell me what color wire I can find in the rear quarterpanel that is attached to that grey wire? I don't see a grey wire in the bundle to the TCM plug. I need to wire whatever wire this is in to the blue wire on my 7 pin trailer plug. Alternatively, I could run a wire directly from the redarc harness to the 7 pin trailer plug, but I'd rather use the existing wiring if possible.

Does anyone have a handy brake signal wire that I can also use? I need a wire that tells me that the brakes have been applied. This will go to the red wire (via the Redarc diode) on the Redarc brake controller.

This is a US delivery 2024 grenadier.

Blue/Orange or violet orange looking one. I tapped in circle area. It is the brown wire you see to the left next to speaker wire, I used to run under batter tray.I had 2 that looked nearly identical. I used a light meter to test when brake pedal was depressed, and light went on= use that line.

Diode in next pic.