PLUNGER AS 8N9130 - Caterpillar

In order to find the cause of a high water temperature shutdown, perform this procedure.Note: This procedure requires the Remote Start Switch to be opened and/or closed many times. In order to ease the troubleshooting process, a switch that is locally acquired can be connected to the terminals of the Remote Start Signal. The terminals are terminal 57 and terminal 30 in the customer connection box.
Check The Obvious Cases.
Check the water level.
Check the fan drive belts.
Check for other obvious causes of high water temperature.Expected Result: No obvious cause exists.Results:
OK: There is no obvious cause. Proceed to the next Step.
Not OK: An obvious cause exists. Correct the fault. Refer to the Engine Service Manual. STOP.
Check The High Water Temperature Function (Check 1).
Open the Remote Starting Switch and then close the Remote Starting Switch.
Allow the water temperature to stabilize.
Check and note the actual water temperature that is showing on the water temperature gauge (WTG).Expected Result: The actual temperature that is showing on the WTG is less than the trip point of the water temperature switch (WTS). High water temperature should not cause the control board to shut down the engine. Results:
OK: The actual temperature is less than the trip point of the WTS and the high coolant temperature indicator is OFF. The problem is not present now. The problem may be intermittent. Check the harness and all electrical connections of the water temperature circuit for the engine. See Testing And Adjusting, "Electrical Connector - Connect". STOP.
OK: The actual temperature is less than the trip point of the WTS and the high water temperature indicator is ON. Proceed to the next Step.
Not OK: The actual temperature that is showing is greater than the trip point of the WTS. The temperature is correct for a high water temperature shutdown. Therefore, the engine should shut down and the indicator for high water temperature should be ON. The WTS and the control board are operating properly. In order to find the cause of the high water temperature, refer to Engine Service Manual. STOP.Note: The operator may check the accuracy of the water temperature sending unit (WTSU) and the water temperature switch (WTS). Install an accurate engine coolant temperature gauge. Place the sensing element in an area of high coolant flow. Place the sensing element as close as possible to the WTS and the WTSU.
Check The High Water Temperature Function (Check 2).
Open the Remote Starting Switch and then close the Remote Starting Switch.
Disconnect the engine harness from the WTS.
Measure the resistance from contact "A" to contact "B" of the WTS.Expected Result: The resistance should measure 5 ohms or less.Results:
OK: The resistance is 5 ohms or less. The coolant temperature is less than the temperature for the trip point. The WTS is faulty. Replace the WTS. STOP.
Not OK: Resistance is greater than 5 ohms. Proceed to the next Step.
Check The High Water Temperature Function (Check 3).
Open the Remote Starting Switch and then close the Remote Starting Switch.
Disconnect the engine harness from the WTS.
Measure the resistance from