NA Trailer Brake Controller Install

[AUDIOBUS]

Thanks all for the guides. I’m finally getting this done…
It was twice the cutting to put the control here (LHD), but it’s an easy reach and I can see it from the driver seat if I lean forward an inch.

 

[LabRat]

Thanks all for the guides. I’m finally getting this done…View attachment 7909802
It was twice the cutting to put the control here (LHD), but it’s an easy reach and I can see it from the driver seat if I lean forward an inch.

Did you still have to go to the rear wiring to pickup the brake control?

 

[AUDIOBUS]

Did you still have to go to the rear wiring to pickup the brake control?

Yes, and I'm with the latest (?) software SW00…969001080

 

[LabRat]

Yes, and I'm with the latest (?) software SW00…969001080

Bummer, not the answer I was hoping for, but it is what it is.

 

[LWA55DAL]

Ok - finally going to run the trigger wire to the RedArc trailer brake controller and I have a question - all of the pictures of the TRM module show a violet/orange wire in 2 locations and based on all of the posts I have reviewed it looks like only one of them actually works and the other one is dead. Has anyone tried to see if the “dead” wire if the wire that is pre-run to the trailer brake controller such that you could just jump the violet/orange at the TRM to the other violet/orange and did it work with the controller? Just trying to avoid running a wire back to the RedArc if the wire coming out of the TRM is supposed to be the one with the trigger and it’s just not wired correctly at the TRM.

 

[AUDIOBUS]

I have reviewed it looks like only one of them actually works and the other one is dead. Has anyone tried to see if the “dead” wire if the wire that is pre-run to the trailer brake controller such that you could just jump the violet/orange at the TRM to the other violet/orange and did it work with the controller? Just trying to avoid running a wire back to the RedArc if the wire coming out of the TRM is supposed to be the one with the trigger and it’s just not wired correctly at the TRM.

See @Clark Kent photo for the "live" wire. (attached)

At least on my truck, the "trailer module" brake wire is dead, both under the back seat and in the rear right corner at the black termination box. The 7 pin connector is live, everything is correct on the outside of the vehicle.

Splice into the brake lights before the loom connector (yellow arrow on clark's photo attached) and you should be good.

If you don't have a helper, jam a pice of wood between the brake pedal and the steering wheel, or seat, take a test light or multimeter and probe the (yellow arrow) connector for the hot pin to make sure you've got the correct wire.

Yes, it's all a PITA, but it's not difficult. You can do it!
~AB

 

[LabRat]

Ok - finally going to run the trigger wire to the RedArc trailer brake controller and I have a question - all of the pictures of the TRM module show a violet/orange wire in 2 locations and based on all of the posts I have reviewed it looks like only one of them actually works and the other one is dead. Has anyone tried to see if the “dead” wire if the wire that is pre-run to the trailer brake controller such that you could just jump the violet/orange at the TRM to the other violet/orange and did it work with the controller? Just trying to avoid running a wire back to the RedArc if the wire coming out of the TRM is supposed to be the one with the trigger and it’s just not wired correctly at the TRM.

Need to test, but I think the violet/orange wire going into pin 2 is the same wire under the seat.

Not being an automotive electrician - so not entirely sure of pin numbering.

1) is the violet(purple) with orange tracer in pin 2?
2) is the wire everyone cutting, the blue with orange tracer in pin 9?

If that is the case, then I will elaborate more.

 

[LabRat]

OK, figured I'd close the loop on this - From what I can tell, the brake controller (TRM) is not sending the signal from pin 9 to pin 2. So the instructions from INEOS are to clip the blue with orange tracer going into pin 9 and wiring in the Redarc diode. Input to pin 2 of the diode and output going into the trailer module to pin 3 of the diode. They want you to pull the violet (purple) with orange tracer from the connector and connect it to pin 1 of the diode.

This is the alternative, INEOS way, to running another wire tapped into the blue/orange wire back to under the rear seat.

So decided to take the plunge and give it a try. These are the two wires going to the TRM that are at issue. BE CAREFUL tracing the wires because I saw TWO/2 violet(purple) with orange tracer wires in the wiring harness. Make sure you clip the right one or go closer to the plug.

I did A LOT of testing at each step of the way with a probe.

Once you tie the violet (purple) with orange tracer wire going back to the BCM to pin 1 of the diode, it comes alive. Here is the Redarc connector showing that the red signal wire is active when you press the brakes.

 

[LowLvlPilot]

Has anyone tried doing this install on a vehicle that did not have a factory TRM/tow package? The same bundle of wires that is used when installing the Off-road gear guys wiring kit, has the same blue/orange wires, but there are three of them. I can't tell which one goes u to where the TRM would be plugged into without pulling back the sheathing.

 

[jrmgren]

I am wiring my in and am seeing the following on my AUS spec 2024 Trialmaster:

Yellow/Red wire = 12v Constant - (REDARC Black Wire) - OK (is it pre fused from factory or do I need an additional fuse?)

Black wire = Ground - (REDARC White Wire) - OK

Violet/Orange 14AWG Wire = Signal (REDARC Red Wire) - Seems OK on mine, it gets 13V when I press the brakes, 0.22V otherwise

Grey Wire 12AWG = Control (REDARC Blue Wire) - This one I am wondering about, with a voltmeter I found no continuity to any of the pigtail pins. What is this connected to exactly? do I need to add the extra pin in position 12 or would I get away with the Narva adaptor?

If anyone could shine a light this would be appreciated

 

[Dougn]

Need to test, but I think the violet/orange wire going into pin 2 is the same wire under the seat.

Not being an automotive electrician - so not entirely sure of pin numbering.

1) is the violet(purple) with orange tracer in pin 2?
2) is the wire everyone cutting, the blue with orange tracer in pin 9?

If that is the case, then I will elaborate more.

View attachment 7914288

For information, on my 25 quartermaster the wire with the yellow arrow in this photo is the brake signal wire position but my color is WHITE WITH AN ORANGE STRIPE. Also getting to the control module in the quartermaster is a huge pain in the ass. The rear seats have to come out and the plastic cover needs to be loosened and pulled back and its all fussy. Really pisses me off

 

[Blackberry Farm]

I''m still confused whether the brake trigger wire of the 4 wires under the seat is functional after the tow package install and software update. Some here say no, but others are posting they've added brake controllers with no problems.
I tried testing the wire by applying the brake and testing for any voltage. Didn't get any, so I assume it's not working. Do you suppose it has to be in Drive to work? It's all software driven, so who knows how it works.

Did you get ever get an answer to your question? I’m in the same predicament. Do I run it to the TRM (right rear quarter panel) or use the factory wire harness under the seat. If I run it to the TRM, where do I plug into… what wire?

 

[Itsdchz]

As I stated earlier in the thread, I didn’t take a chance with the plugged under the seat and ran it to the back as shown in my pictures

 

[Lars]

Did you get ever get an answer to your question? I’m in the same predicament. Do I run it to the TRM (right rear quarter panel) or use the factory wire harness under the seat. If I run it to the TRM, where do I plug into… what wire?

I followed the reccommendation of the post by @LabRat in his post Nov. 26, 2025. This will allow you to use the 4 wires under the passenger seat. He posted some pictures that will help. The other option that I considered is the Curt Echo or Redarc bluetooth trailer brake controller that does not require wiring at all. hope this helps.