Where is the infinity amp in a 2004 dodge ram 1500?

There isn't an "infinity amp" in the standard audio system of a 2004 Dodge Ram 1500. Infinity was an *optional* upgrade audio system offered on some models that year. If your truck has the Infinity system, the amplifier's location will vary slightly depending on the specific trim level and options, but it's typically found underneath the rear seat. You might need to remove the seat or parts of it to access it.