On the 2005 trucks you need to locate the Orange wire with the black stripe, there were two on my plug, I think it was on the row that only had two wires on it. Above those two wires were I think four wires.
At any rate just locate the orange wire with the black stripe then use a test light and roll the dimmer wheel, you will know which one is correct as it dims with the dimmer wheel.
The second orange wire with a black stripe did not light up at all.
One of those wires may have been a dark brown stripe rather then a black stripe, but they sure looked the same to me.