19052A 5 Mercury SWITCH BOX

Illustration 1 g00598786
SchematicTest Step 1. Check for Connector Damage
Verify that the circuit breakers are not tripped.
Turn the circuit breaker for the battery to the OFF position.
Turn the ECS to the OFF/RESET position.
Check connectors and wiring for the following problems: damage, corrosion, abrasion and incorrect attachment.Expected Result:The connectors and wiring should be free of the following problems: damage, corrosion, abrasion and incorrect attachment.Results:
OK - Proceed to test step 2.
Not OK - Repair: Repair the connectors and/or wiring or replace the connectors and/or wiring. Stop.Test Step 2. Check the Air Shutoff System.
Turn the circuit breaker for the battery to the ON position.
Turn the ECS to the STOP position.
Connect the ET.
Access the override on the ET. Activate the override for the air shutoff.
Disable the override for the air shutoff.Expected Result:The air shutoff relay should activate. The air shutoff relay should deactivate after two seconds. While the relay is active, the air shutoff solenoid should also be active.Results:
OK - The system is operating properly at this time. Stop.
Relays ON - The relay activated but the air shutoff solenoid did not activate. Proceed to test step 3.
Not OK - Both the relay and the solenoid failed to activate. Proceed to test step 4.Test Step 3. Check the Relay.
Turn the circuit breaker for the battery to the OFF position.
Turn the ECS to the OFF/RESET position.
Disconnect the wire from terminal 85 and from terminal 86 of the air shutoff relay.
Obtain two suitable pieces of 18 AWG wire. Connect one end of the first wire to -Battery. Connect the other end to terminal 85 of the air shutoff relay.
Connect one end of the second wire to +Battery. Connect the other end to terminal 86 of the air shutoff relay for two seconds.Expected Result:The air shutoff solenoid should activate when the wire is connected to +Battery.Results:
OK - The relay is operating correctly. The problem is most likely in the wiring.Repair: Repair the connectors and/or wiring or replace the connectors and/or wiring. Stop.
Not OK - The air shutoff relay did not activate. The problem appears to be in the air shutoff relay.Repair: Temporarily install a new air shutoff relay. Ensure that the problem is no longer present. Reinstall the old relay. If the problem returns, replace the air shutoff relay. Stop.Test Step 4. Install a Jumper Wire.
Turn the ECS to the OFF/RESET position.
Disconnect P1 from the ECM. Remove the wire from P1-28.
Install a wire at P1-28. Reconnect ECM connector P1.
Connect the red probe of the multimeter to -Battery. Connect the black probe of the multimeter to the socket of the wire at P1-28.
Turn the circuit breaker for the battery to the ON position.
Turn the ECS to the STOP position.
Access the override on the ET. Activate the override for the air shutoff.This test will cause a 446-05 CID-FMI to be logged. Be sure to delete this CID-FMI when this test is completed.
Disable the override for the air shutoff.
Turn the ECS to the OFF/RESET position. Remove the jumper wire.Expected Result:The voltage should be 24 5 VDC.Results:
OK - The voltage is correct. The problem is not with the ECM. Proceed to test step 5.
Not OK - The voltage is not correct.Repair: Replace the ECM. Refer to Troubleshooting, "Replacing the ECM". Stop.Test Step 5. Test the Relay.
Turn the circuit breaker for the battery to the OFF position.
Turn the ECS to the OFF/RESET position.
Disconnect the relay.
Obtain a suitable piece of 18 AWG wire. Connect one end of the wire to -Battery. Connect the other end of the wire to terminal 85 of the air shutoff relay.
Turn the circuit breaker for the battery to the ON position.
Turn the ECS to the STOP position.
Access the override on the ET. Activate the override for the air shutoff.
Disable the override for the air shutoff.
Remove the jumper wire.Expected Result:The air shutoff relay should activate. The air shutoff relay should deactivate after two seconds. While the relay is active, the air shutoff solenoid should also be active.Results:
OK - The relay and the solenoid are operating properly.Repair: Temporarily install a new air shutoff relay. Ensure that the problem is no longer present. Reinstall the old relay. If the problem returns, replace the air shutoff relay. Stop.
Not OK - Both the relay and the solenoid failed to activate. Proceed to test step 3.Test Step 6. Check the Air Shutoff Solenoid.
Turn the ECS to the OFF position.
Disconnect the negative wire from the air shutoff solenoid. Disconnect the positive wire from the air shutoff solenoid.
Obtain two suitable pieces for 10 AWG wire.
Connect one end of the first wire to the negative terminal of the air shutoff solenoid. Connect the other end to -Battery.
Connect one end of the second wire to +Battery. Connect the other end to the positive terminal of the air shutoff solenoid for one second.Expected Result:When the wire is connected to the positive terminal, the solenoid should activate.Results:
OK - The air shutoff solenoid activated. The problem appears to be in the system wiring.Repair: Check the air shutoff solenoid. The first suspect location is between -Battery and the negative terminal of the air shutoff solenoid. The second suspect location is between the positive terminal of the air shutoff solenoid and terminal 87 of the air shutoff relay. The third suspect location is between terminal 30 of the air shutoff relay and +Battery. Stop.
Not OK - The air shutoff solenoid did not activate. The problem appears to be in the air shutoff solenoid.Repair: Temporarily install a new air shutoff solenoid. Ensure that the problem is no longer present. Reinstall the old solenoid. If the problem returns, replace the air shutoff solenoid. Stop.