We are towing a 2005 Weekend Warrior 5'er with a 2005 F350 that has an integrated trailer brake controller. The problem we are experiencing is the controller is giving the warning "Check Trailer" intermittently. I doesn't matter if the brakes are being applied or not. Sometimes, it feels like there no brakes at all, then suddenly they grab and lock up the trailer wheels and smoke the tires. Other times the light warning comes on without locking up the brakes. Sometimes the warning comes on just driving down the road not braking at all.

The truck has been to Ford service twice. The replaced the factory-installed 7-way plug on the bumper (that we have never used) and a fuse. The problem never went away. An RV repair shop replaced the 7-way plug in the bed (that we do use), and eliminated the butt-connectors by removing the factory-installed 4-way plug on the bumper and direct-connecting to the new bed-plug. They also replaced the plug end on the trailer wiring. The problem is not resolved. Currently the truck/trailer are at a different repair shop to see if they can figure it out.

We have had to cancel three trips in the last couple months, but we CANNOT cancel our trip next week. I need working brakes. I NEED HELP!! PLEASE... does anyone have any ideas on what is wrong???

Here is my previous thread for more info (disregard the part where the problem is fixed...!)
https://www.ford-trucks.com/forums/8...any-ideas.html

Thanks in advance,
~~Kath

 

Check the ground connections on the truck, controller, trailer and THE GROUND CONNECTION THROUGH THE PLUG.

 

A big PLUS ONE on ALL ground connectionS, they are ALWAYS the hardest to diagnose!!..

DON't forget the ground connections on the trailer!

ab