Trailer brake errors
Thread Starter
Junior Member
Joined: May 2025
Posts: 5
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Trailer brake errors
When I hook my camper up to the truck & turn the trailer mode on I get power to the trailer lights but when I try to pull the camper the trailer breaks are engaged. I had a friend hook up his truck and he could pull the camper no problem so I’m sure it’s an issue with my F150. I’ve checked associated fuses and they looked fine. I tried swapping out the trailer tow hitch wire harness socket plug but that didn’t work either. I’m at a loss. Anyone had this problem before? 2021 f150 XLT
Senior Member First F150
Joined: Apr 2020
Posts: 4,708
Likes: 1,981
From: Boston, Ma
Good job testing trailer.
So presumably a used purchase? Was the TBC factory fitted or after initial purchase? The window sticker will indicate trailer and a charge if you have factory fitted system.
Too many people have tried adding a TBC aftermarket with factory looking switch without success due to ebay scams.
Have you tested the lighting? Brake, turn and marker lights? You can do that both from inside the vehicle and on the App.
Check fuses.
Finally if nothing works, selling dealer should fix it as they sold you a vehicle without functioning system. M
search function on forum or google may bring other thoughts worth testing.
So presumably a used purchase? Was the TBC factory fitted or after initial purchase? The window sticker will indicate trailer and a charge if you have factory fitted system.
Too many people have tried adding a TBC aftermarket with factory looking switch without success due to ebay scams.
Have you tested the lighting? Brake, turn and marker lights? You can do that both from inside the vehicle and on the App.
Check fuses.
Finally if nothing works, selling dealer should fix it as they sold you a vehicle without functioning system. M
search function on forum or google may bring other thoughts worth testing.