Thread: D4 Electric Trailer Brake Wiring

I didn't fit a diode to my D4's sense wire for the P3.

I haven't managed to find where they hid the "electronics box" for my tow pro yet but here's the controls.

Originally Posted by sniegy

Pin 7 is L/H Tail Light circuit & runs from the CJB down the L/H/S of the vehicle to the wiring harness plug.
Don't forget this wire starts as a "Brown" wire from the CJB & the goes into a Splice joint then becomes 2 wires.
Brown-Pin 5 L/H park light circuit (we modify this to feed the Electric trailer brake circuit)
Black-Pin 7 R/H park light circuit.

Hey Sniegy, question regarding the wiring diagram for trailer brake controller, with the current sensing that happens at the negative battery terminal (I think I understand this correctly) wouldn't it be better to connect the negative side of the power supply to a ground stud?

Originally Posted by BJM

I haven't managed to find where they hid the "electronics box" for my tow pro yet but here's the controls.

It's upside down

It's very hard to operate the headlight switch when it's upside down too

Originally Posted by rufusking

Hey Sniegy, question regarding the wiring diagram for trailer brake controller, with the current sensing that happens at the negative battery terminal (I think I understand this correctly) wouldn't it be better to connect the negative side of the power supply to a ground stud?

All connections to the -ve side of the "Battery" go to the Earth stud as previously mentioned.

Cheers

Hi Guys,

Have been reading the various comments on the electric brakes. have a 2012 D4, fitted with Tekonsha p3 controller, works a treat. Collecting a brand new 2014 RRS end this week and will need to fit a new controller to this. Any ideas about the connection or if they will be different from the D4 ?. I was hoping for the "Grey plug" that is mentioned in other forums, but i see now that they are only in the USA versions. I did not fit the unit into the D4, so need some advice for the new one.

Regards

Terry

I wouldn't assume any wiring similarity between the 2014 RRS and the D4 as the RRS now uses FFRR wiring, eg the battery and main fuse panel are in the rear.