4 wire switch at brake pedal. Which wire do you tap for brake controller?

[Scottlyscott]

I'm trying to figure out where to connect the red wire on the brake controller. I was told I could connect it to the Center High Mounted Stop Lamp behind the back seat but I can't tell which wire to connect it to.

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[Richard2212]

I'm trying to figure out where to connect the red wire on the brake controller. I was told I could connect it to the Center High Mounted Stop Lamp behind the back seat but I can't tell which wire to connect it to.

Look for a existing connector the you can add an aftermarket Brake Controller. Usually the Controller includes a harness adapter. You shouldn't have to splice any wire.

You could pull the Stop Light and look at wire colors. Trace back to Brake switch or do a Google search!

You could also Search this site - you are not the first person trying to do what you are trying!

 

[Scottlyscott]

Look for a existing connector the you can add an aftermarket Brake Controller. Usually the Controller includes a harness adapter. You shouldn't have to splice any wire.

You could pull the Stop Light and look at wire colors. Trace back to Brake switch or do a Google search!

You could also Search this site - you are not the first person trying to do what you are trying!

I've been searching google for days and can't find anything on the Maverick hybrid. Everything shows connecting to a normal 2 wire connector. I've also read that because the braking system is tied to the power regeneration, it could pose problems if you hook it up wrong and someone else suggesting that those 4 small wires go to a computer instead of the lights and there may not be enough power to make the brakes work properly. Also, I couldn't find an available plug under the dash to plug into. Wish someone could take a picture to show me where that plug is. Thanks for your response!

 

[BlueSpec1]

I guess tapping into the CHMSL wire for a trailer brake controller's input and fused +12V to power the brake controller is how to do it as I don't know that there is a separate connector for it on the hybrid.

Center High Mount Stop Light is from the passenger side mounted BCM on C2280F Pin 57, a Yellow/Gray wire that runs to C475 connector above the headliner.
The CHMSL's harness plugs into C475.
Picts look to have Black, White, Orange wires to the light assembly. Orange for 3rd brake light.

https://www.mavericktruckclub.com/forum/threads/23-hybrid-towing-gulp-3k.52933/post-929265

https://www.mavericktruckclub.com/f...ht-when-adding-a-diy-canopy.53430/post-938246

YL/GY wire that was tapped at BCM in another Maverick by dealer:

C475 to CHMSL above headliner:

I do have a (TRM) Trailer Relay Module in my hybrid behind the rear seat.
It's only wired for the 4-pin connector the hybrid has with a hitch.

It's missing the wires that would go to a 7-pin connector for Brake, Charge.
I dont know if it is the same module that would be in a Maverick with 4K tow.

C4397A
11 CAT28 (YE) 18 CTRL MOD. - TRAILER TOW # STOP/TURN LAMP LEFT (COLOR TO SAE 1239) 12 GD347 (BK-VT) 10 GROUND - PILLAR C OR QUARTER PANEL LEFT
13 CAT29 (GN) 18 CTRL MOD. - TRAILER TOW # STOP/TURN LAMP RIGHT (COLOR TO SAE 1239)
14 SBB91 (BU-RD) 10 FUSE - 91 OR CIRCUIT BREAKER

Missing the Blue and Orange wires on C4397B connector.

edit:
Pulled up a VIN for a 2024 XLT AWD w 4K Tow Package: VIN: 3FTTW8J91RRA51026

Did a ford.parts.com search for the TRM using that VIN.
Ford lists it as "module trailer bracket brake".

4K Tow Package - 3FTTW8J91RRA51026
https://parts.ford.com/shop/en/us/a...ule-trailer-bracket-brake-p-nz6z19h332a?pdp=y
module trailer bracket brake
Part #: NZ6Z19H332A
Usage: 08/16/2021 - 11/11/2024, Maverick 2022-, With Trailer Towing Hitch;08/16/2021 - 11/11/2024, Maverick 2022-, With Class II Trailer Towing Hitch
Section: Vehicle Modules and Sensors
This part fits your 2024 Ford Maverick | VIN Build Date: 01/30/2024


2.5L Hitch w 4-Pin - my 2.5L VIN
module trailer bracket brake
https://parts.ford.com/shop/en/us/a...ule-trailer-bracket-brake-p-nz6z19h332a?pdp=y
Part #: NZ6Z19H332A
Usage: 08/16/2021 - 11/11/2024, Maverick 2022-, With Trailer Towing Hitch;08/16/2021 - 11/11/2024, Maverick 2022-, With Class II Trailer Towing Hitch
Section: Vehicle Modules and Sensors
This part fits your 2023 Ford Maverick | VIN Build Date: 09/19/2023


4K Trailer Brake Switch: Integrated Brake Control. Electronic Brake (Trailer Tow) Control. Switch
https://parts.ford.com/webapp/wcs/s...lectrical/switches/accessory-switch-p-sw8839#
VIN: 3FTTW8J91RRA51026
accessory switch
Integrated Brake Control. Electronic Brake (Trailer Tow) Control. Switch Trail Control. Console Floor Sliding - Black
Part #: SW8839 (ML3Z14529AC)
Usage: Black, 08/16/2021 - 11/11/2024, Maverick 2022-, With Class II Trailer Towing Hitch
Section: Instrument Panel Related Parts
This part fits your 2024 Ford Maverick | VIN Build Date: 01/30/2024

SW8839: Switch looks like 4 pins: +12V, Gnd, Illumination, LIN to TRM.

Harness Connector Plug for switch: Molex 1x4 pin Mini50 PN 34791-0040
https://www.molex.com/en-us/products/part-detail/2065230041
Terminals:
Service Part Number LU2Z-14474-AA
Molex 560023-0423
Molex 560023-0721
https://www.molex.com/en-us/part-list/560023

My TRM doesn't have Brake, Battery Charge, LIN wiring on TRM connector C4397B
View attachment 212166

My C4397A looks like has same wires as 4K TRM

2023 2.5L TRM in my truck:
View attachment 212171

 

[MakinDoForNow]

I'm trying to figure out where to connect the red wire on the brake controller. I was told I could connect it to the Center High Mounted Stop Lamp behind the back seat but I can't tell which wire to connect it to.

There is a fuze labeled "after market brake controller". Sorry don't have manual with me.

 

[Scottlyscott]

You're AWSOME!!! That was it and what I needed. Thank you so much!!!

 

[MakinDoForNow]

You're AWSOME!!! That was it and what I needed. Thank you so much!!!

Did it have a harness wire and/or did you find one. Since it's a 30 amp should be enough for a 7 pin controller? I also wonder if it allows the computer to detect the existence of attached trailer to turn off the related items. Let us know please?

 

[Scottlyscott]

Did it have a harness wire and/or did you find one. Since it's a 30 amp should be enough for a 7 pin controller? I also wonder if it allows the computer to detect the existence of attached trailer to turn off the related items. Let us know please?

I see that the 30amp fuse is in the #40 slot but don't know where you plug into it. I am about to go under the dash to find any available hot wire then remove the fuse to find out (hopefully) where the wire is to plug in to.

 

[BDennis]

I see that the 30amp fuse is in the #40 slot but don't know where you plug into it. I am about to go under the dash to find any available hot wire then remove the fuse to find out (hopefully) where the wire is to plug in to.

Scott,

Did you ever find what wire to tap into the center brake light? Running a Ready Brake tow bar that mechanically pulls the brake pedal, but to verify it is working a wire needs to run from the Maverick brake light to an LED in the motorhome dash.

 

[Mavster Mechanic]

Scott,

Did you ever find what wire to tap into the center brake light? Running a Ready Brake tow bar that mechanically pulls the brake pedal, but to verify it is working a wire needs to run from the Maverick brake light to an LED in the motorhome dash.

So.....

why not tap the center brake light?
I did. Simple to unscrew it from the outside. Simple to use a fish tape to fish the wire inside the wall behind the back seats. Then I fished my wire under the center console. I have one continuous weathertec floor mat in the back so no one can see or step on the wire going from back seat to center console.

 

[BDennis]

Thanks

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