The oil pressure sending unit on a 1994 Chevy Blazer with a 4.3L V6 is located on the
passenger side (right side) of the engine block, near the front. It's usually a relatively small unit with one or two wires connected to it. You'll likely need to look closely, possibly using a flashlight, to find it. It's typically near the oil filter but not directly on it.
Because there can be slight variations between engine configurations, a visual inspection of your specific engine is recommended for precise location. Consult a repair manual or online diagrams specific to your vehicle's year and engine for a clearer picture.
