SIDEBOARD AS 8W7938 - Caterpillar

Illustration 1 g02973716
(1) Common
(2) Relay coil
(3) N.C. contact
(4) N.O. contact
(5) Relay coil
Table 1
Switch Position Resistance
OFF Pins 1 and 2 : Less than 5.0 Ohms
RUN Pins 1 and 2 : Less than 5.0 Ohms
Table 2
Machine Shutdown Function Does Not Respond to Operator Console
Troubleshooting Test Steps Values Results
Test Step 1. Machine Power / Engine Crank switch on the Remote Control Operator Console
A. Place the machine in remote control mode.
B. Start the Machine from the Operator Console.
C. Switch the Machine Power / Engine Crank switch on the Operator Console to the Machine Power Off position.
Power is cut to the machine, which causes the engine to stop. OK – The engine stops.
STOP.
Not OK – The engine does not stop.
Repair: Check the E-Stop LED on the transceiver. The LED should be Off. If the LED is Of, the relay in the transceiver may be bad. If the E-Stop LED on the transceiver is illuminated Green, the Machine Power / Engine Crank switch on the Operator Console may be bad. Ensure that the Operator Console is powering down.
Proceed to Test Step 2.
Test Step 2. Visually Inspect the Machine Power Relay in the Remote Control Electrical Center.
A. Inspect the Engine Start Relay.
Check the housing for cracks or other damage.
Check the relay for damaged, burnt, or bent terminals.
The relay shows no signs of damage. OK – The relay shows no signs of damage.
Proceed to Test Step 3.
Not OK – The relay appears damaged.
Repair: Replace the relay and check machine operation.
STOP.
Test Step 3. Test the Machine Power Relay in the Deenergized State
A. Remove the electrical power from the ECM.
B. Disconnect the relay from the circuit.
C. Verify the operation of the relay in the deenergized state.
D. Measure continuity across the following terminals of the relay:
Terminal 1 to terminal 3
Terminal 5 to terminal 2
Terminal 1 to terminal 4
Refer to Illustration 1. The following results were obtained:
Terminal 1 to terminal 3 indicated a short circuit.
Terminal 5 to terminal 2 indicated some measured resistance.
Terminal 1 to terminal 4 indicated an open circuit.
Refer to Illustration 1. OK – Each measurement was correct.
Proceed to Test Step 4.
Not OK – A measurement was incorrect.
Repair: Replace the relay and retest the circuit.
STOP.
Test Step 4. Test the Engine Start Relay in the Energized State
A. Apply the appropriate voltage across the coil of the relay.
Refer to Illustration 1.
The following results were obtained:
Terminal 1 to terminal 3 indicated an open circuit.
Terminal 1 to terminal 4 indicated a short circuit.
Refer to Illustration 1. OK – Each measurement was correct.
Proceed to Test Step 5.
Not OK – A measurement was incorrect.
Repair: Replace the relay and retest the circuit.
STOP.
Test Step 5. Check