TUBE ASSEM. 4W6789 - Caterpillar

Possible Cause 6
There is a failure with the cable for the water valve or the potentiometer.
Determine the type of control for the water valve that is being used 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 the machine in order to make sure that the cable is attached to the water valve handle.
Check the water valve making sure that the valve opens completely when the temperature control knob is moved to maximum heat.
Check the machine in order to make sure that the potentiometer is attached to the wire harness within the dash of the cab.
Check the water valve making sure that the valve opens completely when the temperature control knob is moved to maximum heat.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 valve making sure that the 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