i googled what you said in case I have been wrong all my life as an ASE tech and didn't find anything that supports your statement..
i found the opposite..
modern automobile has a 12 volt electrical system. A fully charged battery will read about 12.5 volts when the engine is not running. When the engine is running, the charging system takes over so that the voltmeter will read 14 to 14.5 volts and should stay there unless there is a heavy load on the electrical system such as wipers, lights, heater and rear defogger all operating together while the engine is idling at which time the voltage may drop. If the voltage drops below 12.5, it means that the battery is providing some of the current. You may notice that your dash lights dim at this point. If this happens for an extended period, the battery will run down and may not have enough of a charge to start the car after shutting it off. This should never happen with a healthy charging system because as soon as you step on the gas, the charging system will recharge the battery. If the voltage is constantly below 14 volts, you should have the system checked. If the voltage ever goes above 15 volts, there is a problem with the voltage regulator. Have the system checked as soon as possible as this "overcharging" condition can cause damage to your electrical system.
If you think of electricity as water, voltage is like water pressure, whereas amperage is like the volume of water. If you increase pressure, then more water will flow through a given size pipe, but if you increase the size of the pipe, more water will flow at a lower pressure. An ammeter will read from a negative amperage when the battery is providing most of the current thereby depleting itself, to a positive amperage if most of the current is coming from the charging system. If the battery is fully charged and there is minimal electrical demand, then the ammeter should read close to zero, but should always be on the positive side of zero. It is normal for the ammeter to read a high positive amperage in order to recharge the battery after starting, but it should taper off in a few minutes. If it continues to read more than 10 or 20 amps even though the lights, wipers and other electrical devices are turned off, you may have a weak battery and should have it checked.
What can go wrong?
There are a number of things that can go wrong with a charging system:
Insufficient Charging Output
If one of the three stator windings failed, the alternator would still charge, but only at two thirds of its normal output. Since an alternator is designed to handle all the power that is needed under heavy load conditions, you may never know that there is a problem with the unit. It might only become apparent on a dark, cold rainy night when the lights, heater, windshield wipers and possible the seat heaters and rear defroster are all on at once that you may notice the lights start to dim as you slow down. If two sets of windings failed, you will probably notice it a lot sooner
It is more common for one or more of the six diodes in the rectifier to fail. If a diode burns out and opens one of the circuits, you would see the same problem as if one of the windings had failed. The alternator will run at a reduced output. However, if one of the diodes were to short out and allow current to pass in either direction, other problems will occur. A shorted diode will allow AC current to pass through to the automobile's electrical system which can cause problems with the computerized sensors and processors. This condition can cause the car to act unpredictably and cause all kinds of problems.
Too much voltage
A voltage regulator is designed to limit the voltage output of an alternator to 14.5 volts or less to protect the vehicle's electrical system. If the regulator malfunctions and allows uncontrolled voltage to be released, you will see bulbs and other electrical components begin to fail. This is a dangerous and potentially costly problem. Fortunately, this type of failure is very rare. Most failures cause a reduction of voltage or amperage.
thats just 1... out of 30 or so pages they all say the same thing... an alternators regulator doesn't control low voltage only high voltage...
can you show me where it says it differently please?
