BRACKET 8J3457 - Caterpillar

Illustration 1 g03715928
(1) Water temperature sensor Diagnostics
Illustration 2 g03717721
Partial electrical schematic
(A) Connector
(B) Connector
(C) Connector
(D) Connector
(1) Water temperature sensor
Disconnect water temperature sensor (1) connector from connector (D). Measure the value of the resistance in the water temperature sensor. See "Specifications" for the correct resistance value. Proceed to Step 2.
If the resistance value is incorrect, see Step 3. If the resistance value is correct, see Step 4.
Replace the water temperature sensor.
Measure the voltage between the "GY/YL" wire and the "GY/BLU" wire at connector (D). See "Specifications" for the correct voltage. Proceed to Step 5.
If the voltage value is incorrect, see Step 6. If the voltage value is correct, see Step 7.
Disconnect connector (C) from connector (B). Check the wiring harness between connector (D) and connector (C). Repair the wiring harness if faulty. Also, check the system power source. Refer to Systems Operation, "Air Conditioning System Electrical Schematic".
Reconnect the water temperature sensor connector to connector (D). Measure the voltage between "GY/YL" wire and the "GY/BLU" wire at connector (B). See "Specifications" for the correct voltage. Proceed to Step 8.
If the voltage values are incorrect, see Step 9. If the voltage values are correct, see Step 10.
Disconnect connector (A) from the control panel. Check the wiring harness between connector (B) and connector (A). Repair the wiring harness if faulty.
Reconnect connector (C) to connector (B). Measure the voltage between the "GY/YL" wire and the "GY/BLU" wire at the control panel. If the voltage value is incorrect, replace the control panel. Specifications
Illustration 3 g02317256
Water temperature sensor characteristics
(R) Resistance (k Ohms)
(T) Temperature Resistance in the water temperature sensor 0 °C (32 °F) ... 1.645 kΩ 25 °C (77 °F) ... 5 kΩVoltage between connectors ... 5.0 VVoltage between terminals 10 °C (50 °F) ... 3.43 V 20 °C (68 °F) ... 2.88 V 25 °C (77 °F) ... 2.59 V 30 °C (86. °F) ... 2.32 V