Trailer Connection
06-25-2015, 02:06 AM
#1
Member
Thread Starter
Join Date: Apr 2011
Posts: 66
Likes: 0
Received 0 Likes
on
0 Posts
Trailer Connection
Hey guys question I have a 2014 F250 when I plug my trailer wiring harness into the truck on the hitch. The info screen still shows trailer disconnected this never happened before. In turn the electric brakes will not work inside the truck using the factory brake controller. However all lights inside and out work on the trailer. Help!!!
06-25-2015, 09:04 AM
#3
Senior Member
A simple test would be to check current draw on the trailer brakes. An amp meter between the batt.(+) pin and the brake pin (on the trailer plug) should register about 3 amps per magnet. A 4 wheel brake trailer should draw about 12 amps. Most RV shops have one of these. As far as trouble shooting yourself, start with the connections at the brake drums. They operate in a fairly hostile environment and can be broken or corroded fairly easily. Also check the ground for the brake circuit. It usually comes back to the junction box near the hitch. It sounds like you have an open circuit condition as opposed to a short. A short will produce a "Trailer Fault" message.
06-25-2015, 12:22 PM
#4
Member
Thread Starter
Join Date: Apr 2011
Posts: 66
Likes: 0
Received 0 Likes
on
0 Posts
I'm using the round seven pin. And guys I mean the truck won't recognize it and it use to. I plug it in and then the display screen on the dash still says trailer disconnected. All the lights work on the trailer so there's power going to the trailer.
06-25-2015, 08:19 PM
#5
Senior Member
Open up the junction box on the trailer and check the master ground tie. Usually there will be one large (10 ga.) white wire screwed into the box. All the trailers circuits will ground back to this wire. They will all be twisted together with a large wire nut. It's not uncommon for one wire to get pushed out as the nut is twisted on. My Montana 5th wheel had this problem when new.The "Trailer Disconnected " message means no continuity / lack of a complete circuit. A test light is misleading when chasing an electric brake circuit under this circumstance because when you stick the brake wire you will be giving it a ground and you will get a light, making you think the circuit is good when its not.
Whether the various tail lights work or not has no bearing on the brakes. There are 5 seperate power feeds going to the trailer, 6 if it has reverse lights. None of them are connected and must be diagnosed individually.
Whether the various tail lights work or not has no bearing on the brakes. There are 5 seperate power feeds going to the trailer, 6 if it has reverse lights. None of them are connected and must be diagnosed individually.
Last edited by PerryB; 06-25-2015 at 09:01 PM.
06-26-2015, 07:24 AM
#7
Senior Member
My pleasure, good luck.