Where is the oil pressure sending unit on a 2000 Chevy s10 4.3l v6?

The oil pressure sending unit on a 2000 Chevy S10 with the 4.3L V6 is located on the driver's side (left side) of the engine block, near the front of the engine. It's a relatively small unit with one or two wires connected to it. You'll likely need to look closely and possibly use a flashlight to spot it. It's usually near the oil filter, but not always directly on top of it.