I purchased a new truck that came with a 7-pin round male setup, but my trailer is a six pin round female, as well as several other of my vehicles. They new truck is a 1997 ford F350XL with a 351 W. My trailer has an electric brake. I bought a new 6 pin male setup for my truck and wired it as follows: Yellow Wire- Left Turn Signal (LT) Green Wire _ Right Turn Signal(RT) White- Ground(GD) Brown- Taillights(TM) All of these work fine, but this is where I am running into a problem: I cannot get the brake lights or electric brake on the trailer to work, and now the brake lights are not working on the truck either. I have three wires remaining: RED-BLACK -BLUE. But only two terminals on the new plug. one reads: (A) and the other is (S). I have tried every different combination, but no avail. I believe the middle terminal labeled (A) is auxiliary, when I plugged the blue wire in to that the brake lights on both the truck and trailer stayed on with out the brake peddle depressed. I also tried splicing the RED and BLUE together in the (S) terminal, which is the brake but that didn't work either. The truck is equipped with a electric brake controller that appears to work fine. Anyone know how to fix this problem?