Low Engine Coolant Level Indicator

The Low Coolant Lamp (Diesel Engines only) illuminates to indicate that the radiator has a low coolant level. Battery voltage is available at the Engine Coolant Level Indicator Module through the PNK (39) wire from GAUGES Fuse 4 when the Ignition Switch is in Run or Start. The module is grounded at Ground G201 by the BLK (150) wire. The module senses a variable resistance to ground at the Low Engine Coolant Level Indicator Sensor through the LT GRN (1478) wire. The sensor has a resistance of 50,000 ohms or more when the coolant level is low. The resistance decreases to about 10,000 ohms when the radiator is full. The sensor is grounded at G109 by the BLK/WHT (151) wire. The Low Coolant Lamp lights when the resistance to ground is approximately 50,000 ohms or more.