Brakes are Broke

[4x4ord]

I’ve got disc brakes on my fiver …. they stop the trailer great but something seems broke. If I set my truck to electric over hydraulic I get a “trailer disconnected “ warning if I apply the brakes momentarily then release and reapply the brakes …. release again and reapply the brakes again. It happens every time on the third application. When the ‘trailer disconnected “ message is displayed the brakes continue to function as expected. I’ve got two identical 2022 F350s and both trucks behave the same way when hooked to that trailer (the only trailer I have with electric over hydraulic brakes). Another bit of interesting observation is that if I set my brake controller to “electric” rather than “electric over hydraulic” I don’t get the message. What do you all think? Is there a problem with my trailer or Ford’s software? The first time I noticed this was pulling the trailer with my 2022 ….. but it’s possible something happened to the fiver since my “21 was hooked to it. For instance I did accidentally leave the emergency brake away unplugged for about an hour which kept the hydraulic pump running nonstop which in turn got the brake fluid and wiring extremely hot.

[opnspaces]

Admittedly no idea. But I would probably get a wire, even an old set of jumper cables and make a temporary ground. Just connect from a bolt or bare piece of steel on the trailer to a bolt on the truck and try again. It doesn't cost anything and only takes a minute to eliminate a grounding problem.