electric trailer brakes only working in reverse

 Just had a braking system put in the car  and its only activating the trailers brakes when in reverse also does the same with a mates car  what could be the problem


Vinesh87's picture

Posts: 2751

Date Joined: 02/04/11

 The trailer brakes are wired

Sat, 2016-04-30 12:44

 The trailer brakes are wired in the reverse pin on your trailer plug but on the carthe socket is wired for reverse lights. Its very common when using a 7 pin plug instead of the 12 pin you are supposed to use!

Posts: 68

Date Joined: 15/09/14

 Is it as simple as swapping

Sat, 2016-04-30 12:52

 Is it as simple as swapping it around "the wires"

scottnofish's picture

Posts: 1621

Date Joined: 28/08/07

You need to have a hot 12v

Sat, 2016-04-30 15:58

 Wired on your car to the reverse light pin to charge the battery and run the brakes 

roddo's picture

Posts: 486

Date Joined: 16/10/09

 Depending on how it was

Sat, 2016-04-30 17:59

 Depending on how it was wired up if done professionaly i would take it back if not then the reverse wire on the car should be removed and a 12v hot wire replaces it. If only working when in reverse it sounds like the active wire is in the reverse pin and not in the brake pin. If that all makes sense. 

Where are you located. It should be a simple fix mighy be as simple as swapping some pins around.

t bone's picture

Posts: 351

Date Joined: 20/04/14

Common mistake.

Wed, 2016-05-18 17:06

A lot of these new brake controllers will have a "signal" wire (generally the blue  core running to pin #5) but then also require a "voltage supply" wire to run the brakes. As others have said this is commonly used via the #2pin (black core) thats labled as the "reverse" wiring. 

Hence the reason the brakes will only work in reverse. Your getting the signal when ever you activate the brakes, but dont have a voltage supply there untill its energized when in reverse. 

I made this same mistake after a few beers when rewiring my ute a while back. As i have 2 sockets on the back of my  ute, i have wired one up that has reverse light ability, then the other has a seperate 12v supply feeding the #2pin for elect brakes.

Posts: 408

Date Joined: 12/03/10

Same problem

Wed, 2016-05-18 17:42

 Some trailer brakes require a main feed from the battery I had the same problem took it to a sparky and ran a main wire feed from the battery problem solved