Where is the oil pressure switch on a 1999 Chevy S10 4.3 V6?

The oil pressure switch on a 1999 Chevy S10 4.3L V6 is located on the driver's side (left side) of the engine block, near the oil filter. It's usually a small, single-wire switch and might be difficult to see without some maneuvering. You'll likely need to consult a repair manual or online diagrams specific to your year and engine for the precise location. A picture search online for "1999 Chevy S10 4.3L V6 oil pressure switch location" can also be helpful.