2015 SD 6.7

I'm installing the USGear Unified Brake System control in the truck cab and hope that the FTE brain trust can provide some answers before I go rooting around in the electrical system.

1) Where does one find the power coming off the brake switch (when activated) and connect into it for a supplemental brake system?
2) Where does one find a positive "switched" power source and connect to it?

Thanks in advance. . .

 

I usually go straight to the brake switch myself, It always seems handy and should be easy to find. The only problem you might run into is, it could be a switched positive or negative. You'll need someway to test it.

Can't help exactly on the accessory wire but the fuse box is usually a good place to tap into.

Bill

 

The 2015 workshop manual shows the wire to be Blue-Orange (BU-OG) after it exits the BCM. I would not connect it prior to the BCM, i.e., the switch on the brake pedal. There is Fuse 31 that is classified in the owners manual as

Customer access
Trailer brake controller (brake signal)

There are two locations to find the BU-OG wire. One is near the heater (workshop manual says right kick panel but connector photo show closer to heater and TPMS module) or near the trailer brake controller where it might change color to Yellow-Green (YE-GR) at connector C2108.

Hope this helps

 

double post....please delete

 

Good info there Larry.
I checked with a buddy of mine - he's got the identical rig and supplemental braking system that I have (2015 SD diesel).
He spliced into the "violet-white" wire behind the brake pedal and installed a diode in-line with his supplemental wire.
He says it works.

However. . .
I'm thinking that your Blue-Orange wire is the way to go. . .probably easier if it can be accessed at the trailer plug at the rear of the vehicle.
Here's what I found so far:







#1 is off the brake pedal. #2 looks to be near the trailer wiring harness.

I will look into using #2 if I can find it.

 

I think that I found a blunt cut near the rear trailer plug.
The picture is upside down so that you can read the factory tag.
Looks like a point to tap into the brake light system.
I will know more tomorrow when I do the testing.

 

Yeah, the blue wire is from the center high stop light - but it's too far to run a wire back to the dash.
Instead, I tapped into the center high stop light inside the cab.