Diagnosing an electrical problem can give even the most knowledgeable technicians difficulty.
Problems (often called "defects") are manifested in alternators and starters that many times can be traced to malfunctions in wiring and other electrical accessories on a vehicle.
Bad connections are a major cause of electrical failures on vehicles today. Many dollars have been spent on batteries, starters, and alternators needlessly because of dirty battery connections. Whenever you have trouble starting your vehicle, always check the battery connections first. You may save yourself considerable time and money.