ENGINE ARRANGEMENT 7N3700 - Caterpillar

Symptom: The heat that is within the cab is uncontrollable.
Possible Cause 1
The water valve is installed incorrectly or backward.
If the machine is equipped with a water valve control, check the water valve in order to make sure that the water valve is installed properly.
Some water valves are manufactured so that there is an arrow that shows the flow direction on the side of the valve body. Make sure that the arrow is pointed toward the line that leads to the heater coil.
If the machine is equipped with a cable driven water valve, make sure that the cable is not wrapped around the water valve, or that the cable is not wrapped around the frame of the machine.
If the machine is equipped with an electronically driven water valve, make sure that the actuator is attached securely to the water valve. Possible Cause 2
There is an electrical failure with the control panel.
Inspect the control panel in order to make sure that the control panel is receiving power when the machine is turned on.
Check in order to make sure that the wire harness is connected to the control panel.
Inspect the wire harness for any breakage or exposed wires.
Inspect the circuit breaker or the fuses in order to ensure that there is not an open circuit. Possible Cause 3
There is a failure with the cable for the water valve or the potentiometer.
Determine the type of water valve control that is present on the machine.
If there is a cable that is attached to the water valve, continue to Step 3. If the machine has a built-in potentiometer, continue to Step 5.
Check in order to make sure that the cable is attached to the water valve handle.
Check in order to make sure that the water valve opens completely when the temperature control knob is moved to the position of maximum heat.
Check in order to make sure that the potentiometer is attached to the wire harness within the dash of the cab.
Check in order to make sure that the water valve opens completely when the temperature control knob is moved to the position of maximum heat. Symptom: There is a coolant smell that is present within the cab.
Possible Cause 1
There is a leak that is present at the hose or the hose clamps.
Inspect the connections between the heater coil and the heater hoses.
Check the hoses for cuts.
Check in order to make sure that the hose clamps are tightened to the proper torques that are shown on the dimension drawings. Possible Cause 2
There is a leak that is present at the heater coil.
Inspect the heater coil in order to determine if there are any visible cracks or holes in the tubing.
Check in order to make sure that the hose clamps are tightened to the proper torques. Possible Cause 3
There is a leak that is present at the water valve.
Inspect the water valve for any damage.
Check in order to make sure that the hose clamps are tightened to the proper torques.
If the water valve passes both these