My driverside boat trailer brake & directional light does not work, only the running light works.
I also have an 05 Titan and the trailer lights work properly with this truck.
I have tested with a cheap LED tester and found that the LH prong has no juice with the brake or directional on. I've had this happen intermittently and before I could get home and fix it, it would start working. I've shaken and rattled the receiver a million times and never been able to duplicate the problem until now. I went to bring my sled trailer to storage and the problem came back.