Radiator Shutter Circuit Description LG5
The ENG Circuit Breaker supplies voltage to the load side of the Ignition Relay.
The IGN 1 Circuit Breaker supplies control voltage to the Ignition Relay. The Ignition Relay is energized when the Ignition Switch is turned to the START or the RUN position. The Ignition Relay then supplies voltage through CKT 639 (PNK) to the Radiator Shutter Control Valve. Current flows through the control valve through CKT 36 (LT GRN) to the Radiator Shutter Engine Coolant Temperature Sensor.
When the coolant temperature is below 90.6°C (195°F) the sensor remains closed. When the sensor is closed, current is allowed to flow through the sensor ground to CKT 150 (BLK), completing the circuit. Either air pressure or oil pressure then flows through the Radiator Shutter Control Valve in order to close the Radiator Shutter.
The coolant sensor monitors the engine coolant temperature. The coolant sensor opens when the coolant temperature reaches 90.6°C (195°F).
The following actions occur when the sensor opens:
| • | The circuit opens. |
| • | The Radiator Shutter Control Valve closes. |
| • | The air pressure or the oil pressure is bled off. |
| • | The Radiator Shutters open. |
