* Coolant Temperature Sensor: This sensor, located in the engine block or cylinder head, is the primary input for the ECM to determine when to activate the cooling fan. This is the closest thing to a "fan sensor." Its exact location will vary slightly depending on the engine (L98 or ZR-1). A service manual for your specific engine is needed for precise location.
* Air Conditioning (A/C) Pressure Switch: When the A/C is on, this switch signals the ECM to activate the cooling fan to assist with A/C condenser cooling.
Therefore, you won't find a single component labeled "fan sensor." Troubleshooting fan issues requires checking the coolant temperature sensor, the A/C pressure switch, the ECM's control signals, the fan relay, the fan motor itself, and its wiring. A wiring diagram and a service manual specific to your 1990 Corvette's engine (L98 or ZR-1) are crucial for proper diagnosis.
