Many years ago, you could disconnect a battery cable while the engine was running to test the alternator in your car. If the engine continued to run, that proved the alternator was working. But it’s a test you should never try on a modern car because they are equipped with computers and electronics. Disconnecting a battery cable while the engine is running causes the alternator to spike a 25-125-volt surge within 40 milliseconds after cable removal. That voltage spike can’t damage anything in an old non-computerized car, but it can instantly fry the many computers and expensive electronics used on all modern cars. Repairing the damage can cost a small fortune.
If your car was built after the early 1970s, chances are it has at least one computer. So forget this old trick left over from the “old days” and test your car alternator with a volt meter. Or, take your car to an auto parts store that offers a free charging system diagnostic test. Schedule an appoinment today HERE