April 2020

48 AFTERMARKET APRIL 2020 ROTATING ELECTRICS www.aftermarketonline.net W ithout starters and alternators, your customers won’t get very far. Understanding how they can go wrong will keep you ahead of the problems, when they arise. In addition, in a complex world, there is something comforting in working on something that has clear perameters, and that you understand. Nothing stays the same though, and if you think you know all there is, it is worth reminding yourself that the tech has gone through some changes over the years. . “DENSO first introduced its automotive alternators back in the 1960s, said DENSO Assistant Manager, Aftermarket Network UK and Ireland, Mike Sadler. “Since then, it has pioneered a variety of new alternator designs, which are capable of producing more electrical power, more efficiently – but in a smaller and lighter unit – therefore, its technical expert is perfectly-placed to reveal what causes repeated alternator failures.” Commenting on the causes of alternator failure, Mike said: “Alternators can fail for many reasons. The symptoms vary from a faulty battery warning light to intermittent charging or no charging at all. In troubleshooting, it is essential to start identifying the symptoms first in order to narrow the possible causes. A visual inspection of the system and its components will also help. “One of the common causes for alternator failure is a bad diode, burnt out due to an open circuit or high resistance between the alternator output (B+) and the positive (+) battery connections. In these circumstances, charging current will flow through the diodes from an alternative route towards the battery. “This alternative route will cause excessive flow through the diode, resulting in the alternator overheating and, ultimately, failing. Should this issue arise, DENSO’s best practice advice is for technicians to perform a thorough inspection and conduct voltage drop tests to isolate any problems and avoid alternator failures in the future.” Mike continued: “A similar effect may occur when the alternator is forced to charge a discharged battery or when the battery can be charged but can’t be set-up to normal resistance. “In such cases, the alternator will be instructed to charge the battery to the maximum rate and be overloaded for prolonged periods of time, which will cause the alternator to overheat. As a result, the diodes, as well as the stator windings and connections inside the unit, can become damaged and fail. Once referring to DENSO’s best practice procedures, technicians should check the battery and replace if necessary. Mike concluded: “Overheating can also occur if the alternator is positioned in a space with poor airflow, especially when the component is working under full load at slow speed and in conditions where cooling is insufficient. This may result in an early alternator failure.” “When it comes to replacing car parts,” said Anders Nielsen, Starter and Alternator Product Manager from BORG Automotive, “many people consider two options, OE parts or the traditional aftermarket component. But there is a third option. the remanufactured parts. BORG Automotive proves that this option is more than attractive for all involved: distributors, workshops and car owners. Anders continued: “Let’s take a closer look at how BORG turns original starters and alternators from used into practically new parts.” Cleaning, checking and replacing “First, the specialists from BORG Automotive disassemble the unit,” said Anders. “Each screw, each bearing, each housing is thoroughly cleaned and inspected. BORG even invented machines dedicated to this purpose. Finally, all metal parts are galvanised. A zinc coating for metal parts is superior to other coatings or paint like used by other companies’ and even the OEMs. “Small parts like brushes, bearings, sliding bushings and oil seals are immediately replaced. That is because these ALTERNATOR-IVE FACTS While fake news and alternative facts make the world more confusing, at least there is some reassurance in the certainty of rotating electrics Above: Alternator from BORG Automotive Below: Starter from BORG Automotive