The problem is that you're looking in the wrong place. The engine compartment itself is typically the primary location for this.
Here's how to find it:
1. Open the hood: This seems obvious, but it's the first step.
2. Look for a pulley-driven pump: The power steering pump is typically a relatively small pump with a pulley on it, driven by a belt from the engine. Follow the serpentine belt (if it's a serpentine system) or the individual belts to see where they connect.
3. Look near the engine's front: The pump is often located on the front of the engine, near the alternator and other accessories.
4. Check for a reservoir: The power steering fluid reservoir is often a separate container, sometimes attached to or near the pump itself. It will likely have a cap with a dipstick or markings to indicate the fluid level. This reservoir is where you add fluid.
5. Consult a repair manual: A repair manual specific to your 1972 Dodge Xplorer camper van will show you exactly where the pump and reservoir are located. This is the most reliable way to find it. You can often find these manuals online (eBay, Amazon) or at auto parts stores.
If you still can't find it after thoroughly searching the engine compartment with the help of a repair manual, it's best to consult a mechanic. There might be a unique configuration in your specific vehicle.