An air conditioning crane boom assembly having a number of mounting feet that removably secure the assembly to the rungs of a stepladder. Braces extend from these feet to a boom that extends horizontally away from the rungs of the stepladder. A pulley or a winch may be attached to the base of the boom, near the rungs of the stepladder, and the boom extends away from the stepladder to facilitate safe and stable lifting of loads such as air-conditioner components.