Full Answer
What should the battery voltage be with the engine off?
This should read a little more than 12 volts with the engine off. Next check the voltage of your charging system under load, the voltage should be within 13.2: 14.5 volts d/c. To load, have engine running at idle, turn on headlights and HVAC blower motor.
Why is my car charging but my alternator is not working?
If you suspect alternator trouble, you need to check to see that is operating correctly, and is indeed the cause of the problems with your charging system. Sometimes bizarre electrical problems can be caused by a number of faults other than the alternator. It's important to troubleshoot the system prior to replacing your alternator.
What should I do if my car has alternator trouble?
If you suspect alternator trouble, you need to check to see that is operating correctly, and is indeed the cause of the problems with your charging system. Sometimes bizarre electrical problems can be caused by a number of faults other than the alternator.
What happens when an alternator fails?
The alternator charges the battery and provides your car with a constant source of electricity while the engine is running. Over time, the alternator will begin to fail and cause trouble with the various electrical devices in the car.
What voltage range should an alternator put out?
between 13.9 and 14.8 voltsA good alternator should maintain battery voltage between 13.9 and 14.8 volts (14.2 is optimum). Even worst-case, with all accessories turned on, there should be at least 13 volts at the battery.
How many volts should a 12 volt alternator be putting out?
13-14 voltsA car alternator needs to be putting out at least 13-14 volts (ideally between 13.8 and 14.2 volts) to effectively charge a 12 volt car battery.
What should a good alternator read?
A good alternator should produce about 13.5 to 14.5 volts with the engine idling. If the voltage reading is low (12.5 volts or less), it indicates a charging problem but does not tell you what's causing it. That's why bench testing is so important.
Is 14.7 volts too high?
14.8 would start to be a worry (there might be liquid or corrosion on the battery) and 15 volts would be a real concern, but 14.6 is fine. Less than 14.3 would be a "weak" alternator or regulator. Much less than 14.2 at a fast idle is bad wiring, bad alternator or regulator, or a bad connection or fuse link.
What does an alternator charge?
Click here to order! The alternator charges the battery and provides your car with a constant source of electricity while the engine is running. Over time, the alternator will begin to fail and cause trouble with the various electrical devices in the car. If you suspect alternator trouble, you need to check to see that is operating correctly, ...
Can a belt break on an alternator?
Modern belts seldom break, but they get brittle and glazed with age, and can slip on their pulleys. Replace the belt with a new one as required. The next item to check is the voltage at the battery. Before performing any tests of your alternator, charge and test your battery.
The alternator charges the battery and provides your car with a constant source of electricity while the engine is running
The voltage regulator does just what it says: it regulates the voltage from the alternator. Your battery should read a little more than 12 volts with the engine off. Next check the voltage of your charging system under load, the voltage should be within 13.2: 14.5 volts d/c.
Project Photos
Figure 1 Turn your alternator pulley side down on your bench. The voltage regulator is partially obscured by a plastic cover on the back of the alternator. Remove the two nuts (one 13mm (blue arrow) and one 15mm Yellow arrow)) and the one Philips head screw (red arrow) on the back and then lift the plastic cover off.
Why do people swap out alternators?
A large amount of the time when there is an electrical problem with the charging system it is the voltage regulator, yet people just swap out the entire alternator because it comes with a new voltage regulator included because it is easier, fixes the problem and most people do not understand how an electrical system works on their car.
What does a voltage regulator do?
The voltage regulator does just what it says: it regulates the voltage from the alternator. Your battery should read a little more than 12 volts with the engine off. Next check the voltage of your charging system under load, the voltage should be within 13.2: 14.5 volts d/c.
Can you disconnect a battery cable while running an engine?
Never disconnect a battery cable while engine is running to test alternator, you may cause damage to alternator or other electrical components from the surge in amperage. If your battery appears to be leaking, then your voltage regulator has probably failed.
What is a Alternator Voltage Regulator?
The alternator voltage regulator is a component of the electrical system on a car, truck, or SUV. More specifically, the voltage regulator is part of the charging system responsible for managing the output of the alternator and maintaining a full charge on the battery . It is either housed inside or attached to the alternator.
How does an Alternator Voltage Regulator work?
The voltage regulator works with the alternator to make sure that electrical output stays within 13.5-14.5 volts and that the battery stays charged. A vehicle's battery is used to provide power to start the engine, and it is used to smooth out the supply of electricity when the vehicle is running.
What are the symptoms of a bad Alternator Voltage Regulator?
Symptoms of a bad voltage regulator might include a dead battery, dim or pulsing dash lights, or erratic engine performance.
Can I drive with a bad Alternator Voltage Regulator?
Any time problems occur with the vehicle charging system, immediate attention is required. The voltage regulator is an important component of the charging system. If the symptoms of a bad voltage regulator occur, the vehicle should either be driven to the nearest qualified repair facility, or should be parked and towed.
How often do Alternator Voltage Regulators need replacement?
The alternator and voltage regulator are not maintenance items that have replacement intervals. A factory alternator (with the voltage regulator inside) may last 100k miles or more, however, it is not unusual for an alternator to fail closer to 80k miles due to its moving parts, heat, and internal components that wear.
What happens if your golf alternator goes bad?
If the serpentine belt has gone bad, it can make some noises too, but it won’t sound metallic like the bearings going bad would.
What happens if your golf battery is bad?
When the battery gets so dead it will no longer be able to power your Golf’s ignition system. As the ignition system is no longer able to produce a full powered spark, the engine will begin to sputter and stall.
Do alternators go bad?
Some alternators go bad right away, and some slowly lose their ability to charge under heavy loads. The ones that fail completely are easy to diagnose. The battery drains and you are stuck with a vehicle that goes nowhere.