Dodge: leak, dodge ram 1500, last rain

Question
My 1999 Dodge Ram 1500 club cab leaks. The passenger side carpet gets soaking wet when it rains hard. The truck was assembled in Mexico. I am the original owner and the truck has always set outside. Is there a history of where these trucks usually leak? I cannot find where the water comes from. I suspest the windshield but don't really know. I think it has leaked for a long time but after the last rain the leak allows a lot of water to collect in the passenger side of the truck. No water collects on the drivers side. Thanks for any suggestions you may have.  

Answer
Don,
Climb in the bed of the truck and check the screws in the cargo light.If they are loose retighten them.This is probably where the leak is coming from.And yes there is a history of them leaking.Mine was leaking and it was from this location,the water will run down the back of the cab into the passenger floor board.RamMan