A system is provided for testing the electrical integrity of an implanted pacemaker or defibrillator lead. The system includes a container holding an electrically conductive solution, such as a saline solution. A voltage source and two electrodes are provided to pass an electrical current through the solution. To use the system, the proximal end of the electrical lead is disconnected from the implanted electronic device, passed through the saline solution and then electrically connected to a device/monitor. During testing, the device/monitor sends a test pulse through the lead and monitors electrical activity in the lead. To test sequential locations along the length of the proximal segment, the segment is drawn through the saline solution and between the electrodes while test pulses are sent and monitored. The monitor detects abnormal electrical activity in the lead indicative of a break in lead insulation.