What is the spark plug wiring sequence on a 1986 Chevy S-10?

There's no single definitive answer for the spark plug wire firing order on a 1986 Chevy S-10 because it depends entirely on the engine. The S-10 came with several different engines (2.0L, 2.5L, 2.8L, 4.3L V6). Each engine has a unique firing order.

To find the correct firing order, you must determine your engine's displacement (e.g., 2.8L) and then consult your owner's manual or a reliable repair manual specific to your vehicle's year and engine. The firing order will be clearly stated there, often depicted with a diagram showing the cylinder number and the corresponding spark plug wire sequence.

You can also try searching online using the year, make, model, and engine displacement (e.g., "1986 Chevy S-10 2.8L firing order"). However, always double-check any online information against a reputable source like a shop manual. Getting this wrong can damage your engine.