Which ocean influences more on the humidification of the South American continent. Why?

Despite the fact that South America has almost equally long coastline with both the Pacific and the Atlantic, they unevenly affect the climate of this continent. Moisture from the Pacific Ocean almost does not enter the territory of South America, since the Andes mountain range stretches right along the Pacific coast. They fence off the air masses to the mainland. And from the Atlantic side, there are no mountains, and the trade winds freely penetrate into the interior of the continent. Thanks to them, South America is the wettest of the continents.