The oil pressure switch on a Ford 4.0L SOHC engine is located on the
driver's side (left side) of the engine block, near the oil filter. It's usually a small switch with one or two wires connected to it. You'll likely need to get under the vehicle to see it clearly.
Because there's some variation depending on the exact year and model, it's best to consult a repair manual specific to your vehicle's year and model for a precise location. A picture diagram in the manual will greatly assist in finding it.
