Battery cables are high-current conductors that connect the battery to the vehicles electrical system. Battery cables must be of a sufficient capacity to carry the current required to meet all electrical demands. Normal 12-volt cable size is usually 4 or 6 gauge. Various forms of clamps and terminals are used to assure a good electrical connection at each end of the cable. Connections must be clean and tight to prevent arcing, corrosion, and high-voltage resistance.
FIGURE. The battery cable is designed to carry the high current required to start the engine and supply the vehicle’s electrical systems.
The positive cable is usually red (but not always), and the negative cable is usually black. The positive cable will fasten to the starter solenoid or relay. The negative cable fastens to ground on the engine block or chassis. Some manufacturers use a negative cable with no insulation. Sometimes the negative battery cable may have a body grounding wire to help assure that the vehicle body is properly grounded.
Note: It is important to properly identify the positive and negative cables when servicing, charging, or jumping the battery. Do not rely on the color of the cable for this identification; use the markings on the battery case.
Note: Pinch on battery cable clamps are a temporary repair only!