AC unit dripping onto crawl space vapor barrier
The short pipe looks like it's a condensate drain - which will trickle when the AC is operating. It needs to run to a drain or to the outside. It looks like the insulation over the pipes has been damaged by the condensate running over it, and will need to be replaced. Even if the drain wasn't running onto them, the pipes are cold, so will sweat unless they're well insulated - the C shaped insulation needs taping closed, or you can buy insulation with a ziploc type feature that closes it up.