HARNESS AS 1003618 - Caterpillar

Possible causes for an FMI 3 Diagnostic code are:
The relay has failed
The energize circuit of the relay is shorted to the +battery circuit
The ECM has failed. ECM failure is unlikely
Possible causes for an FMI 5 Diagnostic code are:
The energize circuit of the relay is open.
The return circuit of the relay is open.
The relay has failed.
The ECM has failed. ECM failure is unlikely.Possible causes for an FMI 6 Diagnostic code are:
The energizer circuit of the relay is shorted to ground
The relay has failed
The ECM has failed. ECM failure is unlikelyNote: The diagram above is a simplified schematic of the relays and the Relay connections. The schematic is electrically correct. However, not all of the possible harness connectors are shown. Refer to the latest revision of Electrical Schematic, UENR3921 for the complete schematic.
Table 2
Relay Resistance Table    
(FMI 144) Back Up Alarm Relay    
At (25° C)(77° F)     410 Ω 10%    
(FMI 420) Secondary Steer Motor Relay    
At (25° C)(77° F)     16.24 Ω 10%    
(FMI 444) Starter Motor Relay    
At (25° C)(77° F)     24Ω    Diagnostic Trouble Code Procedure
Note: Prior to beginning this procedure, inspect the harness connectors that are involved in the circuit. Poor connections can often be the cause of a problem in an electrical circuit. Verify that all connections in the circuit are clean, secure and in good condition. If a problem with a connection is found, correct the problem and verify that this diagnostic code is active before performing this procedure.
Table 3
Troubleshooting Test Steps    Values    Results    
1. Identify Active FMI Code Associated With Relay Circuit    
Code present.     FMI 3 diagnostic code, proceed to Test Step 2.
FMI 5 diagnostic code, proceed to Test Step 3.
FMI 6 diagnostic code, proceed to Test Step 5.    
Begin Process For FMI 3 Troubleshooting HERE    
2. Check The Machine Harness For A Short
The relay remains disconnected from the machine harness.
A. Turn key start switch and disconnect switch OFF.
B. Disconnect the J1 and J2 connectors from the ECM.
C. Measure the resistance of the relay signal contact to all other contacts are used in the harness connectors J1 and J2 for the ECM.    
Each reading greater than 5k Ω.     OK - All resistance measurements are greater than 5k Ω.
Proceed to Test Step 7.
NOT OK - One or more readings are less than 5 Ω.
Repair - A short exists between the signal contact and the circuit with the low resistance. Repair or replace the machine harness.
Note: A resistance that is greater than 5 Ω but less than 5k Ω would indicate a loose connection or a corroded connection in the circuit. A resistance measurement that is greater than 5k Ω would indicate an open in the circuit.
STOP    
Begin Process For FMI 5 Troubleshooting HERE    
3. Check the relay
A. Turn the disconnect switch and the key start switch to the OFF position.
B. Disconnect the relay with the active diagnostic code from the machine harness.
C. At the machine harness