To find it, you should:
1. Consult your owner's manual: This is the best place to start. It will have a diagram of the fuse and relay boxes, clearly showing their locations.
2. Check the Power Distribution Center (PDC): This is the most common location for relays, often found under the hood. It's a large box with numerous fuses and relays. Look for a diagram on the inside of the PDC's cover.
3. Look in the fuse box inside the vehicle: Some Dodge vans might have relays inside the passenger compartment fuse box, usually located under the dashboard.
4. Use a wiring diagram: If you can't find it visually, a wiring diagram for your specific van model and year is essential. These can be found online through auto parts stores or repair manuals. You'll need to identify the fuel pump relay by its circuit number.
Without knowing the exact model of your 1996 Dodge van, I can't provide a more precise location. Providing the model will greatly increase the accuracy of any answer.