explain in part 3 the connection between sighting of the ship and the Mariner biting his arm and sucking his blood that he might cry aloud and the scene of the crew members all drinking their blood and shouting for joy.

I think it was due to to fact that he was becoming delirious . Look at the line that states water water everywhere yet not a drop to drink. He was at a point where he did not care anymore and by seeing the ship made him atone to the fact hat he would most likely die on that ship.