ALTERNATOR GP-CHARGING 1416157 - Caterpillar

This problem occurs after the preheat and postheat cycles without the operator pressing the air inlet heater switch. The indicator for the air inlet heater on the monitoring system will come on for 30 seconds after the postheat cycle is finished. The problem may continue to repeat. The possible causes of this problem are listed below:
The signal wire (F842-BU(Blue)) is shorted to ground.
The air inlet heater switch has failed.
The ECM has failed. This is unlikely. Note: Wait for 30 seconds after the last heating cycle was completed before the air inlet heater switch is checked for the problem. Also, before the switch is troubleshot, make sure that the indicator for the air inlet heater and the heater are working properly. Test Step 1. CHECK THE SWITCH.
Turn the key start switch and the disconnect switch to the OFF position.
Disconnect the machine harness from the air inlet heater switch.
At the connector for the switch, measure the resistance between contact B and contact C. Measure the resistance when the switch is pressed. Measure the resistance when the switch is released. Expected Result:The resistance that is measured is greater than 5000 ohms when the switch is released. The resistance that is measured is less than 5 ohms when the switch is pressed.Results:
OK - The resistance that is measured is greater than 5000 ohms when the switch is released. The resistance that is measured is less than 5 ohms with the switch pressed. The switch is correct. Proceed to test step 2.
NOT OK - The resistance that is measured is NOT correct. The switch has failed.Repair: Replace the air inlet heater switch.STOPTest Step 2. CHECK THE MACHINE HARNESS FOR A SHORT TO GROUND.
The disconnect switch and the key start switch remain in the OFF position.
The air inlet heater switch remains disconnected from the machine harness.
Disconnect the J1 and J2 machine harness connectors from the ECM.
At the J1 and J2 machine harness connectors, measure the resistance from the J1-22 (signal) to all possible sources of ground. The possible ground sources are contacts: J1-2, J1-5, J1-7, J1-15, J1-16, J2-3, and frame ground. Expected Result:Each resistance that is measured is greater than 5000 ohms.Results:
OK - Each resistance that is measured is greater than 5000 ohms. The machine harness is correct. Proceed to test step 3.
NOT OK - One or more of the resistance measurements is less than 5 ohms. There is a short in the machine harness.Repair: The short is between wire F842-BU(Blue) (signal) and the circuit with the low resistance measurement. Repair the machine harness or replace the machine harness.STOPTest Step 3. CHECK IF THE PROBLEM IS STILL ACTIVE.
Inspect the contacts and clean the contacts of the harness connectors.
Reconnect all harness connectors.
Start the engine. Expected Result:The air inlet heater is functioning correctly.Results:
YES