Possible Cause 1: Blower motor not working.
1. Check the circuit breaker or fuse box to ensure there are no open circuits in the system.
2. Visually inspect the wiring harness for damage and missing connectors. Refer to the circuit diagram of each machine to ensure correct connections.
3. Check the fan blades to ensure they are not obstructed or jammed.
4. Check that the fan switch functions properly in all settings. The blower motor should be able to operate at various settings and temperatures.
Possible Cause 2: Leakage in the system.
1. Check the hose clamps to ensure they are not missing and tighten them to the torque values shown in the diagram.
2. Check the heating coil for obvious cracks or leaks.
3. Check the water valve to ensure it is installed correctly and functioning properly. 311B TRACK-TYPE EXCAVATORS 2LS00001-UP (MACHINE)
Possible Cause 3: Engine cooling system inlet/outlet closed.
1. Check the valve connecting the heater hose and the engine block.
2. Ensure the valve is fully open.
Possible Cause 4: Hose kinks or blockages in the system connections.
1. Check the hoses for blockages or bends. Blockages and bends in the heater hoses will obstruct coolant flow and degrade the performance of the entire heating system.
2. Replace any hoses that may be obstructing coolant flow.
Possible Cause 5: Heater control malfunction.
1. Determine the type of control device used by the machine.
2. If the system is equipped with a water valve, proceed to step
3. If the system is equipped with a mixing valve, proceed to step 6. 3. Check the water valve for signs of damage.
4. Check the water valve to ensure it is fully open when the temperature control knob is set to the hottest position.
5. If the water valve cannot be opened or closed, proceed to “Possible Cause 6”. 6. Check the mixing door.
7. Check the mixing door for any damage.
8. Ensure the insulation on the mixing door is intact.
9. Ensure the actuator is connected to the mixing door.
10. Check the mixing door to ensure it is fully open when the temperature control knob is set to the hottest position.
Possible Cause 6: The water valve cable or potentiometer is faulty.
1. Determine the type of water valve control device used by the machine.
2. If the water valve is connected to a cable, proceed to step
3. If the machine has a built-in potentiometer, proceed to step 5. 3. Check the machine to ensure the cable is connected to the water valve handle.
4. Check the water valve to ensure it is fully open when the temperature control knob is set to the hottest position.
5. Check the machine to ensure the potentiometer is connected to the wiring harness in the dashboard.
6. Check the water valve to ensure it is fully open when the temperature control knob is set to the hottest position.113
