BUCKET AS-SEVERE SERVICE SPADE 3453308 - Caterpillar

problems are often caused by failed electrical wires that have either an open circuit or a short circuit. If one part of a circuit contacts another part of the same circuit, the flow is diverted from the desired path. This condition would be a short circuit. The following procedure explains the test for a short circuit:Reference: For a complete electrical schematic, refer to the Electrical Schematic for the machine that is being serviced.Test for a short circuit.
Turn the battery disconnect switch key and the key start switch to the OFF position.
Disconnect all ends of the wiring harness.
Turn the dial of a calibrated digital multimeter to the 200 ohm range and measure the electrical resistance.
Use one multimeter probe to touch the connector of the suspected faulty electrical wire.
Use the other probe from the multimeter to check for continuity across all other electrical wires in the same wiring harness. Check all wires for continuity across the frame or ground.
If there is continuity between any of the electrical wires, the multimeter will have a reading of less than 5 ohms. Continuity between any of the other wires in the wiring harness indicates that there is a short between those wires. The wiring harness must be repaired or replaced.
Use the multimeter in order to test for continuity across the frame or ground. If there is continuity between any of the electrical wires, the multimeter will have a reading of less than 5 ohms. If there is continuity between any of the wires and the frame, there is a short between the wire and the frame. Identify the wire that has a short to the frame. Refer to the Electrical System for the machine in order to determine if the wire is a part of the ground circuit. If the wire is not a part of the ground circuit, the wiring harness is damaged and the wiring harness must be repaired or replaced.