MANIFOLD GP-EXHAUST 4N2649 - Caterpillar

Illustration 1 g01276599Specification
This test measures the voltage drop across the main relay and/or the circuit breaker. The voltage drop is measured across test point (9) and test point (12). Test point (9) is the positive contact and test point (12) is the negative contact.A voltage drop will cause the indicator lamp for the main relay and/or the circuit breaker to turn ON. The voltage drop must be larger than 1.30 0.15 volts. The lamp turned ON in order to indicate a low state of charge. A defect can be indicated during any Test Step.The possible causes of this condition are listed:
Activated circuit breaker
Closed circuit breaker with an excessive voltage drop
Open relay contact
Closed relay with excessive voltage drop
Relay with welded contactsNote: It is necessary to find the two components that have a defect if a machine fails this test.Use a digital multimeter in order to find the faulty components. Check for an excessive voltage drop across the man relay (F) and the main circuit breaker (E). Use the multimeter to troubleshoot the conditions for the test step that caused the analyzer to show a defect.Information for Other Circuits
It is possible that a machine will have both of the components. It is also possible that a machine will not have either component.Test point 12 is connected directly to test point 9 on machines that do not have either component. This type of connection will never indicate a defect on the analyzer.Replace the component(s) that is faulty if a machine has a main circuit breaker and/or a main relay.Refer to the wiring schematic for the machine that is being serviced. Use the schematic in order to determine the components that are used in the electrical circuit that is under the test.