What additional items must be inspected on a doubles or triples combination beyond a single trailer?

Doubles and triples have more connections than a single trailer, and every one is part of the inspection. The driver checks each pintle hook (latched, not worn), every converter dolly (its fifth wheel, axles, tires, and lights), all kingpins and fifth wheel locks, the safety chains, and the air and electric lines running between the trailers. The glad hands must be connected and sealed, and the air shut-off (cut-out) valves at the rear of each trailer except the last must be open, with the very last trailer's shut-off closed. Any failure in these between-trailer connections can cause a breakaway or loss of trailer brakes.