I think there's only a single remote line. At least a single BLUE remote line. I believe it's also spliced to the factory tuner connector, but at the ISO connection there's only the one pin.

The sled pin-outs in the FAQ confirm this.

Further, the ISO adapter that's used to mate to the sled's ISO connector only has a single blue remote line coming out of it as well. I know because I used all the wires, except one, during my last install a couple of weeks ago. My left-over wire was the green telephone mute. And I didn't connect any antenna wires.

Bruno