Hi, I just got a new 16" trailer and am trying to sort out a couple things. They both involve wiring which is not my strong suit!!

First, it has a flat 4 plug and only the drivers side stop lights and blinker work. The tail lights don't light up with the headlights and the pass side lights don't do anything (I did check the pass side bulb and it is fine). What is the best way to troubleshoot this?

Second, it does has electric brakes with just a single wire coming up for it. I know I have to get a brake controller and wire it up.

Lastly, it has an electric winch but doesn't have the control cord. I did put power to it and tried to jump the 4 pin connector.. I think I know which one is ground, I found one pin that had power, the other two don't - how do I approach this?

Thanks