Grateful for this forum and hope anyone might have insights! I honestly don't know much about brakes or wiring myself (my DIY has been focused on interior and paint) and am currently working with a mechanic - but he's stuck.
I've had a 1970 Nomad 17ft (~3300 lbs) for about 3 years and took it out every 6 months or so with a borrowed truck. Just got a new SUV and a new Tekonsha P3 brake controller. Had one successful tow but on our way out on a trip it immediately started saying "overload no brakes" or "output short no brakes". This error ONLY happens when it's moving. The braking message gets successfully sent to the brakes and there's no error at a standstill. Took it to UHaul for a quick look, couldn't find anything wrong that wasn't the trailer (brake controller connection, vehicle tow package, breakaway, etc.).
Took it for a more in-depth check, mechanic figures the magnets would be worn. But just heard back that they're fine. He took apart the brakes and can't find anything wrong anywhere. He hooked them up to his truck and it worked at first, then got the error, then it worked again. He has no ideas except to replace the brake backings and hope it fixes it. Any other ideas? Anything quirky and specific to old trailers to look out for?
Also wondering - is the "just replace it" route going to cause more problems - ie. the parts will be incompatible with other pieces and much worse quality?
Last Edit: Apr 9, 2021 12:52:44 GMT -8 by benenomad: added a question