This disclosure relates to a medical electrical lead having fault detection and fault isolation. The lead may include a first conductor coupled to a first electrode and a second conductor coupled to a second electrode. A capacitor is disposed within the lead and selectively coupled to the first and second conductors of the lead. The capacitor is charged in a test mode of operation after the first and second electrodes have been isolated from the conductors via an isolation mechanism and the capacitor will discharge through the first and second conductors. The capacitor discharge morphology is processed to detect lead-related conditions.