Briefly, a method and system for testing a cable harness is disclosed. Generally, a cable harness is used to route many electric wires for power, communication, and control. The tester includes a switch system that enables one or more TDR engines to sequentially apply a TDR stimulus to substantially all the wire pairs in the cable harness, and to collect the resulting TDR waveforms. The waveforms are analyzed to determine if the cable harness meets quality standards. In some cases the tester may also perform a continuity, resistance, capacitance, or inductance test on the cable harness. The tester may also measure and use temperature in analyzing the cable harness, or may apply temperature cycling, different or varying atmospheric pressures, vibration, shaking, or shock to the cable harness.