The South American bird that uses echolocation to navigate in caves is the oilbird.
The oilbird, Steatornis caripensis, is a nocturnal fruit-eating bird found across northern South America and on Trinidad. It nests and roosts in colonies inside caves, where darkness makes ordinary vision difficult. The birds produce rapid, sharp clicks and interpret returning echoes to avoid cave walls and other birds.
Oilbirds are unusual because echolocation is strongly associated with bats and toothed whales, not birds. Their clicking calls are audible to humans and supplement their highly sensitive night vision. Their eyes contain an exceptionally high density of rod cells, helping them forage for oil-palm and tropical-laurel fruits after sunset.
The name oilbird comes from the very fatty chicks, which were historically collected in parts of South America for oil. The species is sometimes confused with swiftlets, which are also among the few birds known to echolocate. However, the oilbird is the distinctive cave-dwelling South American fruit eater described by this question.