Christopher McCann wrote: > and this could vary from one voltage regulator to another, depending on how > it is designed to work, correct? >
Yes. In old cars they were all pretty much the same, but in some modern cars the engine computer actually controls the alternator field windings, and will vary the charging current depending on conditions. For example, on warm days, my Honda Civic would often turn off the alternator completely while idling in traffic. I'd see the voltmeter drop to 12 volts or so. It would start charging again after I resumed speed or if I turned on an electrical accessory, such as the A/C blower. It usually ran around 13.5 volts, but on cold days, after starting the car in the morning, the ECU would call for all-out charging and I'd see a full 14 volts for a while.
