Right turn signal is not functioning. All other lights and functions work properly. Any thoughts as to where I should trouble shoot?

check your trucks fuses, most trucks have seperate fuses for the trailer hookup. or have a buddy hook up to it and see if his truck works?

Good call. Thanks Opti. I can hook it up to wifes SUV.

Most trucks have separate fusing for the trailer. Some have two. One for the running lights, and one for the brakes, turn and reverse lights. Some have separate fuses for left and right turn, Brake, and running lights.

Good idea to check on another vehicle if convenient. For several years, I have had a checker that I plug into the vehicle side. It will tell you if the problem is with the tow vehicle. I think Reese makes it? I don't remember where I bought it. It was cheap, and works everytime.