Keep getting trailer default reading

[SOS Landscaping]

I have an 06 f20 with built in ford tow command on my truck. My 07 enclosed carmate trailer keeps popping up with a trailer fault reading, called the dealer they said it was the ford brake controllers were garbage. Hooked the trailer up to my buddies 05 f250 with built in tow command and same problem. I then tried my friends carmate trailer on my truck and it worked like a charm.
Funny thing is if my trailer is completely empty the brakes work fine no matter what setting. The second I put some weight in the trailer I get trailer fault reading. Someone told me that mayeb it was because they battery is old but it is only a year old to this date. Any ideas?

[Horsepower Lawns]

Some 2005 factory Ford brake controls are bad. Ford will not fix them.

Your problem in a wire is cut and shorting out, its OK unloaded because the wire is not touching anything, but as soon as you put weight on it the wire is getting hit and shorting out.
A dead battery will not do anything, unless you have Elec-Hdy brakes then it may cause some problems.

[SOS Landscaping]

Some 2005 factory Ford brake controls are bad. Ford will not fix them.

Your problem in a wire is cut and shorting out, its OK unloaded because the wire is not touching anything, but as soon as you put weight on it the wire is getting hit and shorting out.
A dead battery will not do anything, unless you have Elec-Hdy brakes then it may cause some problems.

it is an 06 not 05 but its the same styles so I guess it would still be bad. But it works perfectly fine with other trailers so I know its not the truck. I have pulled probably 1/2 dozen other trailers with my truck and the brakes all work fine. So the problem has to be trailer side