Why Can My Boat Trailer Still Back Up When The Reverse Solenoid Isn't In Use

Updated 08/16/2024 | Published 08/13/2024

Question:

I have a boat trailer with surge brakes and it connects to tow vehicle with a 4 way flat but there are 5 wires coming out of connector to trailer. I assume 5th wire is for reverse lockout. It appears to be working but how without a dedicated circuit for backup? Thanks Mike

asked by: Mike O

Expert Reply:

Hey Mike,

The reverse lockout would not be functioning if you're only connecting to a 4-pole connector on the tow vehicle. You likely have free-backing brake assemblies, which allow for the trailer to back up without engaging the brakes. On free-backing brake assemblies the primary shoe is a two-piece design to allow it to push in instead of pushing out against the hub, allowing you to back up.

If you ever want to replace the brake assemblies I would not install a 5-pole harness to use the reverse lockout and instead would go with free-backing assemblies again for an easy fool-proof setup.

expert reply by: Kevin C