Result: Brake Controller with Wiring

. With headlights on, all is correct except the brake lights do not work on the van by itself nor do the trailer | Everything works well on the 1999 plymouth voyager and the trailer 4 pin with headlights off. With headlights...

however my trailers passenger side brake light works but not the blinker same bulb?. I have narrowed | ! have a 1998 Gr. Voyager with this harness installed. All lights on the vehicle work properly however my trailers passenger...

and yellow wires each carry both brake and turn lights. If the 4-pole connector carries the correct | The turn signals work on the trailer but the brake light and light does not. What could be the problem....