The throttle position sensor (TPS) on a 1996 Dodge Ram 1500 is located
on the throttle body itself. The throttle body is situated on the intake manifold, typically near the air filter housing. The TPS is a small sensor mounted directly to the throttle body; it's usually a small rectangular or square unit with a wire harness plugged into it.
You'll likely need to look closely at the throttle body—it's usually a black, cylindrical component with the throttle cable attached. The TPS will be visibly attached to it. A shop manual or online diagrams specific to your engine (e.g., 3.9L, 5.2L, 5.9L) will help with precise location.