Generally speaking, the water pump is located on the front of the engine, typically driven by the crankshaft via a belt. It's usually near the timing belt or timing chain, but again, the exact location varies by engine.
To best find the water pump:
1. Identify your engine: Find the engine code.
2. Consult a repair manual: A repair manual specific to your 1988 Ford Ranger's engine will have diagrams showing the exact location of the water pump. You can find these online (e.g., Haynes or Chilton manuals) or at auto parts stores.
3. Search online with your engine code: A web search including your engine code and "water pump location" might yield images or videos showing the pump's location.
Without knowing your engine, I can't provide a more precise answer.