Where is the gas tank on a silhouette van?

The gas tank on a Dodge Ram Caravan (often called a "Silhouette" due to its similar body style in certain years, though technically not the same) is located on the passenger side (right side in the US), typically under the rear passenger area. You'll need to pop open the fuel door (usually located on the passenger side behind the rear tire) to access it. The exact location may vary slightly depending on the model year and trim.