Trailer Brakes Won't disengage to backup

[spahrs]

I have a 2020 1500 Ram. Just got a new boat trailer with surge brakes and a flat 5 pin plug. I am not getting any power to that fifth pin (blue wire on trailer) to disengage the brakes to back up. I have to manually go put the key in on the trailer to back up. Everything works fine on my friends truck - so trailer isn't the problem. DId some basic wire testign and am getting no power on that pin from the truck side. Everything else works - stop lights, turn signals, etc... I have been searching the fuse panels but can't find anything blown out unless I am missing something. Is there something not hooked up right on the harness on the truck or is there a specific fuse I should be looking at or adding? Any help would be greatly appreciated.

 

[SOKY_RAM]

Just making sure. You are testing that pin with the truck in reverse right? That pin should be hot while your backup lights are on.

 

[spahrs]

Yes, I have the truck running and in reverse (with a friend helping me). The reverse lights come on, but no power to that pin. I am using an adapter to go from 5 pin to the round 7. That adapter works on my friends truck.

 

[SOKY_RAM]

I would test the center pin on your 7 way (no adapter) with your reverse lights on. If it doesn't show power let the dealer figure that out since your truck is brand new.

 

[ToyHaulin]

I bought a Curtis tester to make sure the reverse signal was working on my previous vehicle. My boat trailer has UFP a60 actuator which uses a solenoid valve. I believe the valve recirculates brake fluid to the reservoir, allowing the actuator to compress without sending pressure to the trailer brakes. I keep a lockout pin with the trailer in case this mechanism fails on the road.

 

[crash68]

All 6 powered pins of the 7 pin trailer plug are individually fused. Look for a fuse referencing something like Trailer Tow reverse.