[REDROCKER652002]

My son's truck had a somewhat similar issue. It turned out the connection wire at the bulb housing had come loose. In other words, the three wires that go into the plastic plug that plugs into the back of the taillight, one of those wires had come loose and was not making a connection. Not sure if that is even close to what you are experiencing, but what the heck. I figure I would throw it out there.