Where is the check engine light on 88 Jeep Cherokee?

The check engine light on a 1988 Jeep Cherokee is not a standard check engine light like you'd find in later model vehicles. Instead, it's part of the diagnostic system's indicator lamp. It's usually located on the instrument cluster, often near the other warning lights (like oil pressure, etc.). It may be labeled "MIL" (Malfunction Indicator Lamp) or simply have a picture of an engine. Because the system is simpler than OBD-II systems, it won't always illuminate for every engine problem.