Where is the oil sending unit on 1989 Chevy Silverado?

The oil pressure sending unit on a 1989 Chevy Silverado is located on the driver's side of the engine block, near the oil filter. However, the exact location can vary slightly depending on the specific engine (e.g., a small-block V8 vs. a big-block V8). It's usually a small, cylindrical unit with one or two wires connected to it. You'll likely need to consult a repair manual specific to your truck's engine to get a precise visual location. A picture of your engine would also help confirm its location.