Originally Posted by mercury7
If I am getting power to at least one marker light in the rear, does it seem safe to assume I will have power in my tail lights.... I think they are all just burned out but did not know if they were connected to the maker light circuit
Don't ASSUME your trailer is over 40 years old, could be a broken wire or corroded connection.
The tail lights and running lights are the same circuit.
Break lights/turn signals are 2 separate circuits.
I don't think your lights are burned out, from my experience most exterior trailer lights stop working due to corrosion, not burning out.