In aircraft factories, automated cable test equipments are used at the final stage of harness manufacturing before hooking up process. They try to find whether there is a broken wire or a leakage on cable. This paper examines the continuity (open-circuit) and insulation (short circuit) test operations of an aircraft cable by using Petri net model and also explains operation principle of test equipment theoretically. The proposed model basically identifies aircraft wiring test operations that are applied by automated test equipments and presents all real test conditions in a realistic way. Different from other literature studies, a general model of automated test equipment is tried to model for detecting both open circuit and short circuit faults. Furthermore, this work shows that basic training test equipment can be constructed easily combining adjustable voltage sources, analog to digital converter (ADC), switches and so on.