Less complicated now with more diagnostics. Back in the day you used to simply FRY your wiring in the entire truck if you had a short in your plug. Today the truck will detect this and simply shut it down with no effect on the truck lighting at all.

Both trucks, same issue. Different trailers. Hooked up at the same exact time. Turn the brake controllers up on both trucks and apply the brakes. And both trucks freed up after a few applications of The trailer brake.

Everything is just expensive junk now man. All the company’s care about is keeping the money flowing in to them… We’ve had so many electrical issues, not only with our f550s but our new duramax’s as well. These fords are just a heck of a lot worse, from my personal experience anyways. One problem with any single sensor(or anything really) can cause sooo many problems that (should) have nothing to do with the system having the primary issue.

If the ground is bad, wouldn't all the lights flicker together. The ground is the common. Need its source for anything to work.

@DS-TRUCKS Not necessarily. I have seen some incredibly strange light activity with bad grounds. For example a LED bulb may work, but incandescent flickers. Take apart every ground (including brakes) that may be in the system wire brush, Clean metal with isopropyl alcohol, install clean quality connectors and cap seal with RTV silicone both sides of ground screws/bolt after reassembly. The reason running up the brake controller may temp fix it is essentially you are cooking through (arcing) the resistance in one of the ground connections supplying it max voltage. The reason the hyperflashing is happening on one side is the truck isn't detecting enough resistance, again, more than likely due to the ground on that circuit. This is SO important to do if you live in an area where a ton of road salt is used. If you look in the old plug, you can see the discoloration from a bad connection, more than likely corrosion. Replacing the plug is a great idea. Fill that SOB with dielectric grease, both sides. Spent many years working on commercial jets and corrosion is your enemy. Good luck!

@@jarrsong this trailer had a completely smoked ground at one point. Burned through. Gage was too thin

@DS-TRUCKS WOW! This is very common when folks discover that they trailer brakes aren't functioning at strong as they should. The ground return path is too small or corroded. In airplanes, the ground paths are designed into the structure to follow a critical path with resistance of this path in the .000x ohms resistance. You want the voltage spike, say from a lightning strike to with no exceptions follow a perfect path through the structure of the aircraft. Same with your trailer. If a larger system ground is corroded/compromised, it will then follow a path of a smaller ground, possibly even a greased trailer ball or safety chain. I had a trailer one time that I was borrowing that I backed up to so I could check the lights, but didn't hitch up to. NO lights, EXCEPT for 3 clearance lights, 2 on one end and one on the other. After screwing with it for some time I hitched it up to move it in shop to work on it and the suddenly the lights all worked. What? Wait? The main ground on the frame end of the trailer wiring was bad, but the hitch was enough of a ground to light everything. Why the three clearance lights lit, I have no idea but more than likely they had a better ground path, possible from a mounting screw of the light itself.