From time to time, inspect all of the battery cables along their entire length for damage, cracked or burned insulation and corrosion because shoddy battery cable connections can cause starting problems as well as reduce engine performance. Inspect the cables' connections to the terminals for cracks, corroded wire strands and looseness. Presence of white fluffy deposits beneath insulation at the cable terminal connection indicates corrosion and need for replacement. Look at terminals for distortion, missing hardware and corrosion. When disconnecting cables always start with negative then only connect it last in an effort to prevent shorting out the battery. Disconnect old cables, ensuring that new ones are of equal diameter and length with initial one. When purchasing new ones together with others ensure you take these old ones as a guarantee that they will fully match. Red colored larger diameter positive cables have a larger diameter battery post clamp while black smaller in diameter ground cables have a slightly smaller diameter clamp for the negative post. Use a wire brush to scrape away rust and corrosion from relay or ground connection threads before applying light coating of battery terminal corrosion inhibitor or petroleum jelly that will stop future corrosions from occurring on them again.Attach the mounting nut/bolt securely so that it does not get loose after fixing the cables on relay or ground connection.Before connecting any other cable into a cell make sure it reaches battery post without stretching.Clean batteries posts thoroughly using this liquid or petroleum jelly to cut out any form of corrosion from occurring.Connect positive cable first followed by negative one.