Is the alternator on a newer car always on (using power), or does it cycle on and off according to need.?

Answer 1

It doesn't (use power) it generates it.
And it doesn't cycle, it regulates the amout supplied.

Answer 2

The alternator on a car is always ON(while the engine is running) This is why you will see a higher voltage 14.4ish while running compared to 12ish while engine is off.
Your alternator is rated by how many amps it can supply small cars are normally 65-90 amps where trucks can be 80-170 amp. Some cars needing lots of DC power for lights and things like police cars will have dual output alternators giving 140 on two circuits.
Your alternator is not always pumping out its max current; in fact it only puts out what it needs to keep the voltage regulator happy at the 14.4 volts on the DC side. The alternator dose this because it is creating AC electricity with a magnetic field, the more demand the regulator puts on the field the more current produced, also causing more drag on the motor. A alternator putting out 100 amps will be harder to turn then one putting out 20amps, this is why your car will burn more fuel with the more electrical things you use in your car(lights, radio, heater fan, A/C..ect).

If you are noticing your lights dimming, or a drag on the system like the altinator is shutting off, it just might be something turning on as the computer calls for it placeing a load on the system, the best way to combat this dimming is for a larger battery that can store more amps to buffer the sudden load change from hitting the alternator so hard.

Answer 3

If all things are good the voltage on a battery should be around 12.5 volts with the engine dead, the voltage on the same battery will be around 13.7 volts with the engine running given the alternator and voltage regulator are good.

If the Volts on the battery remain the same (12.5) when started you have a bad voltage regulator or alternator

The battery supplies just enough dc current to the alternator to provide an electromagnetic force in the stators of the alternator when the ignition switch is closed

Answer 4

Some of the new cars will greatly reduce the amount of charge from the alternator in a situation where not much electrical load is being placed on the electrical system.

Answer 5

cycles on and off to prevent system over load unless you are running a masive stereo system, in a snowstorm with heat cranked, all ten fog lights going turning left with the wipers on warp speed...then it's on all the time.

Answer 6

regulator is the so called brain of the alternator .

Answer 7

i own a repair shop,and most of them now days still cycles ,unless it has an option on the car that runs all the time ,like daytime running lights,then this keeps it on all the time but most of them now still cycle ,,but like i said some of them are on all the time,,good luck,i hope this help,s.