l am rewiring a bout trailer with old wiring still on it. Can you help/

Why do not you want running lights on it? By law, you have to have running lights on it or it will not pass a safty check. You can buy a whole harness in one piece at any marina. Very easy to put it on.

It is best to replace the entire wiring harness. You should replace the lights that came with the trailer to remain compliant with the law. You can find replacement harnesses from many sources. Running lights do not require any additional wiring, they tap into the wires that run to your rear lights (parking lights).

in the US trailers without brakes are wired as follows:

brown wire (one each side) => tail lights
yellow => drivers side brake/turn signal
green => passenger side brake/turn signal
white => ground -- secure to a bolt at a rust-free unpainted part of the trailer frame

the light fixtures are grounded to the trailer frame