Alright, my dad and I are totally stumped on this one. The trailer that I rewired is not working correctly on my truck, but it works fine on my dads. When the trailer is hooked up to my truck the running lights work, but as soon as you put the brake on, the lights go off instead of getting brighter. When the trailer is on my dad's truck everything works how it is supposed to. The wiring that comes off of the trailer goes into a 4-pin connector and then goes to an adapter to fit in my 7 plug hitch. To check and see if it was my truck wiring we checked the current coming out of the adapter. Everything checked out on my truck and my dad's. That is why this is so confusing. Any suggestions would be appreciated.