Trailer Brakes Quit Working While Hitched to the Trailer

Question:

I have a 2016 dodge ram and a brand new 2019 dump trailer for it. The issue is this, once if I connect my 7 pin to the truck WITHOUT connect the trailer to the ball, I have trailer brakes. But as soon as I connect the trailer to the ball of the truck, a message on my truck kicks on that the trailer brakes are not connected, the weir thing about it is, I will still have lights to the trailer. What would be the cause of this and how would I go about fixing it? I have already re-wired the trailer without any help and have traced is back to the ball being connected being the issue. Is there anything like this that you have seen? I am willing to try anything at this point.

asked by: Mitchel B

Expert Reply:

The issues you described is certainly an odd one but it sounds like this may have something to do with a bad ground. If you are able, I recommend you try to use a different tow vehicle or a different trailer to see which side the issue is occurring on. If you cannot do so then you will just need to redo your grounds on both the truck and trailer. Starting with the truck, remove the ground for the 7-way and reattach it to a bare metal spot. I would then check to make sure the wire is securely attached to the back of the 7-way in the correct location.

Once the above is complete you can then turn your attention to the trailer where I believe the issue is occurring. Similar to what we did to the vehicle 7-way we will want to do the same for the trailer 7-way. Then, once this is done we can check the ground for the braking assemblies. I have attached a photo to show how these grounds should be ran.

If all else fails it may be time to just take the truck/trailer into a service center.

expert reply by: Conner L