C 1500 Truck 2WD V6-262 4.3L VIN Z (1992)
Coolant Level Indicator Lamp: Description and Operation
The Low Coolant Indicator comes on to warn the driver when a low level of coolant exists in the radiator. Battery voltage is applied to the Low
Coolant Module. When a low coolant condition exists, a signal is sent to the Low Coolant Module from the Low Coolant Sensor. The Low Coolant
Module will provide a ground to the Low Coolant Indicator.
The Low Coolant Sensor is not a switch that opens and closes. It has a very high resistance to ground, more that 50,000 ohms, when the engine coolant
level is low. This causes the Low Coolant Module to illuminate the Low Coolant Indicator. With more of the Sensor covered by coolant, its resistance
decreases. When the fluid level is good, the resistance will be less than 10,000 ohms. With the Sensor resistance between 10,000 and 50,000 ohms, the
Sensor is partly covered and the fluid is not low enough to cause the warning to be displayed.
