ADAPTER 6N4306 - Caterpillar

problems are often caused by failed electrical wires that have either an open circuit or a short circuit. If one part of the circuit contacts another part of the same circuit, the flow is diverted from the desired path. This would be short circuit. Perform the following in order to test for a short circuit:Test for a short circuit.
Turn the battery disconnect switch key and the key start switch to the OFF position.
Disconnect both ends of the wiring harness.
Turn the multimeter dial to the 200 ohm range and measure the electrical resistance.
Turn the multimeter probe in order to make contact with the connector of the suspected faulty electrical wire.
Use the other probe from the multimeter to check for continuity across all electrical wires in the same wiring harness and check all wires for continuity across the frame to 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 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 circuit between the wire and the frame. Identify the wire that has a short to the frame.ReferenceTo determine if the wire is a part of the ground circuit refer to the Electrical System Schematic.If the wire is a part of the ground circuit and the wiring harness is damaged, the wiring harness must be repaired or replaced.