I have a 2003 Express van, from what I can tell they don't make a t-connector for this application. So yesterday I wired in a flat connector to match my trailer (4 wire) and now my trailer lights aren't working properly. What did I do wrong and how do I fix it? Thanks in advance for your help.
Jamie

what doesn't work?? ground a testlight and probe the pins of the connector did you wire it as follows?
brown=park lights
green=right turn/brake
yellow=left turn/brake
white=ground