My car will not start. It is completely dead (zero power), is it my alternator?

This morning I went out and my car had zero power. I thought it was the (brand new) battery so I attempted to jump the car. The power came on and I got the engine to turn over but the car would not stay on. I checked and there are no loose belts, but I noticed a whining noise yesterday whilst driving and my alternator wires are all black, though no other obvious issues. There were no warning lights at all on since my last repair. Can I reasonable assume it is my alternator that is the culprit?
My car has an automatic transmission.
Experienced mechanics share their insights in answering this question :
A failed alternator is a possibility, and is among the components that would be checked first, but it is not the only possibility. Charging system output should be verified against factory specifications. To have the alternator inspected and replaced, if necessary, please request an alternator inspection/replacement and the responding certified mechanic from YourMechanic will get this resolved for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

How to Identify and Fix Common car Problems ?

Our sources include academic articles, blog posts, and personal essays from experienced mechanics :

If your vehicle won`t start, it`s usually caused by a dying or dead battery, loose or corroded connection cables, a bad alternator or an issue with the starter.
If you`ve replaced your battery but the engine still won`t start, it could actually be an engine problem. A seized engine won`t turn over, and that often resembles a bad starter or dead battery. If you suspect that your problem stems from an engine issue, it could take hours to diagnose and repair.
The most common reasons a Jeep had no power relate to the fuel system or the Jeep battery. Other common reasons include wiring issues, a bad alternator, or exhaust issues. Start with checking the battery and that the engine is getting fuel.
An alternator cannot do everything a charger can. For starters, an alternator can charge a battery with a low charge, but it cannot charge a dead battery.
Bad Sensors

One common culprit for this problem is the crankshaft position sensor, which measures the position and speed of the crankshaft. The computer uses the information from this sensor to know when to fire the spark plugs. If the sensor isn`t working, the spark plugs won`t fire, keeping the engine from starting.

Broken or Damaged Ignition

If your headlights can turn on, but your car won`t crank, that means that your battery is charged, but either the starter or ignition is the problem. If the starter or ignition is the problem, a starter engine can be jumped by using a charged battery.

A car can only run for a very short time with a failed alternator. This is because the alternator charges the battery when the engine is running. Once the battery is depleted, the vehicle will die and fail to restart.
The most common reasons a Jeep Grand Cherokee won`t start are a dead battery, an alternator problem, or failed starter. Search our network of RepairPal Certified shops near you to speak with a technician about your issue.
It could be a bad battery, failing starter, or some other component in the electrical chain that comprises the starting system. The starter typically consists of two main components: the motor itself and a solenoid used to switch positive battery voltage to a motor terminal.
If your alternator fails when you`re far from home, you can typically drive up to 200 miles on battery power alone. That`s assuming your battery is in good shape and fully charged. Of course, it`s best to get the alternator repaired or replaced as soon as you can.
If your battery is sulfated, which results in low power and difficulty in recharging to full capacity, it can sometimes be recovered using proper pulse charging techniques. Wehmeyer warns, however, that there are an infinite variety of pulse charging techniques used by a wide variety of equipment sold for this purpose.
One of the best ways to determine if a car fuse has blown is by using a test light. It should illuminate both ends of the fuse, and, if it doesn`t, it needs to be replaced. Sometimes, a blown fuse is caused by a damaged wire, motor, or other part.
The O2 sensor will not cause the no start. The no start can be caused by the fuel pump or the ignition system. You should check the engine for spark and fuel pressure, when it is not turning on to help narrow the problem down. The ignition system may be the coil, module, or pick up in the distributor.
The crankshaft position sensor monitors the position and speed of the crankshaft and other parameters that play an important role when starting the engine. If the crankshaft position sensor is having a problem, the vehicle may have intermittent starting issues or not start at all.
Yes, you can drive with a bad oxygen sensor if you can still start your engine and feel little difficulty driving. But don`t leave it alone for over a couple of days, as it might cause safety problems and lead to the malfunction of other parts of your vehicle.
The most common causes for a Jeep failing to start despite its radio and lights working are issues relating to its battery or other cranking/start-up components, such as the ignition switch, starter, or spark plug. These pieces might be damaged, dirty, or corroded.
Symptoms of a burnt out diode:

The engine will begin to run rough, lack power and eventually stall and not start again. The battery warning light will turn on, warning you that there is a problem with your alternator charging system. The headlights will become dim due to reduced battery voltage.

One of the most common problems you`re likely to experience with an alternator is a failure in the bearings. There are needle bearings in the alternator that allow the rotor to freely spin inside the housing, and those bearings can break down over time as a result of exposure to heat and dirt.
The most common reasons a Jeep Cherokee won`t start are a dead battery, an alternator problem, or failed starter.
Slow engine cranking – When you attempt to start your Jeep, especially when it`s cold outside, it cranks over slowly. This is a classic sign of a failing battery. The battery “dies” easily – If your Jeep isn`t running and you leave your lights on, the battery should power the lights for 10-15 minutes.
The first is to check the wiring from the battery to the starter. They should be looking at voltage drop across the starter circuit. They should also be looking at the starter and neutral safety switch. The second issue may be the key fob is weak.
There are several issues that can ruin an alternator: Using jumper cables wrong, Overloading the charging system with too many accessories, Leaking fluid, or.
If a faulty alternator fails to keep your battery consistently charged, the fuel injectors may not fire, causing your engine to stall. A dying alternator can lead to a wide range of other electrical issues. Generally speaking, such issues manifest as an inability to perform at normal power.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

My car will not start Intermittently. I purchased a new battery 2 weeks ago and yesterday the car wouldn’t start. Got a jump and
ANSWER : The issue you are having is probably due to an intermittent fault in the starter motor itself or a deficiency in the starter electrical circuit, for example a large voltage drop due to a poor ground or a high resistance connection. These issues can be readily diagnosed and resolved on a mobile basis if you request a hard starting diagnostic. If you request that diagnostic, the responding certified mechanic will get this resolved for you promptly. Based on Toyota’s Factory Service Manual, the battery should not be disconnected if the vehicle engine is running. The battery acts as a large resistive voltage sink and consequently taking the battery out of the circuit, while the alternator is still running, can create a voltage spike on the car’s electrical system which is not good for voltage sensitive components such as the engine computer. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

Read Full Q/A … : My car will not start. It is completely dead (zero power), is it my alternator?

My car will not start. It is completely dead (zero power), is it my alternator?
ANSWER : A failed alternator is a possibility, and is among the components that would be checked first, but it is not the only possibility. Charging system output should be verified against factory specifications. To have the alternator inspected and replaced, if necessary, please request an alternator inspection/replacement and the responding certified mechanic from YourMechanic will get this resolved for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

Read Full Q/A … : My car will not start. It is completely dead (zero power), is it my alternator?

Map sensor car won’t start up good ?
ANSWER : Your MAP sensor is an important input for your computer. It helps determine the load on the engine to calculate the correct amount of fuel to inject. It sometimes takes a few seconds for the vehicle to realize that the sensor is not producing a good signal.

At that point, it will use other methods to determine the fuel rate, such as pre-programmed fuel maps, throttle position, etc. I would suggest replacing the MAP sensor and retesting. If you would like to have it checked first, a certified technician from YourMechanic will be able to scan your vehicle and test components to determine the root cause of your starting issue before making a repair.

Read Full Q/A … : My car will not start. It is completely dead (zero power), is it my alternator?

2005 Chrysler 300C changed battery and alternator. Car started, ran, and then battery light came on. Shut car off and wouldn’t start.
ANSWER : Hi. There is a couple of things that could be wrong here. The battery or alternator that was just installed could be defective. Theses parts need to be tested for proper operation. There also could be a fuse, fusible link, or wiring for the battery or charging system that is blown or broken causing the battery light to come on.

The codes that you have will cause the car to shut down, run rough, or not start at all. The crankshaft sensor and camshaft sensor should be replaced. I suggest having a certified technician from YourMechanic come diagnose the charging system and check engine codes to help you proceed with correct repairs.

Read Full Q/A … : My car will not start. It is completely dead (zero power), is it my alternator?

EPC light on and started losing power as well as taking longer to start the car. now the car wont start
ANSWER : Hi There,
The EPC light is typically related to the ECM (computer) not receiving the proper signal from the crankshaft position sensor. A crankshaft position sensor is an electronic device used to monitor the position or rotational speed of the crankshaft. This information is used by engine management systems to control the fuel injection or the ignition system timing and other engine parameters. When this is faulty or not working properly, this will cause problems with the ignition system and generating spark transmission to the spark plugs resulting in starting problems and other performance issues causing misfires. I would recommend having an expert from YourMechanic come to your location to diagnose and inspect your vehicle.

Read Full Q/A … : My car will not start. It is completely dead (zero power), is it my alternator?

I have a 1992 Honda Accord EX and I’m having an issue with the car not having power to the dash at all and doesn’t start.
ANSWER : Hi there:

The symptoms you’re describing are often an indicator that a problem exists with the alternator or charging system such as an electrical relay. Before you spend another penny trying to chase the symptoms by purchasing more parts, it’s best to have a professional mobile mechanic complete a battery does not hold a charge inspection. This service will allow them to correctly diagnose your Honda Accords issues.

Read Full Q/A … : My car will not start. It is completely dead (zero power), is it my alternator?

Charging warning light comes on when i turn the key and try to start the car and the car want start but when someone tried to give
ANSWER : Hi there:

If you recently replaced your battery, the issue may be caused by a malfunctioning alternator or other electrical component that comprises the charging system on your Nissan Sentra. The best way to find out which item specifically is faulty, is to have a professional mobile mechanic complete a car is hard to start inspection. This will allow the mechanic to determine the precise source of what’s going on with your Sentra and recommend or complete the right repairs.

Read Full Q/A … : My car will not start. It is completely dead (zero power), is it my alternator?

car hesitates when trying to start the car ,but when started then i shut car off and start again it will start right up
ANSWER : Hi there:

Sometimes when you have problems starting an engine initially it is caused by a restriction in fuel flow; caused either by clogged fuel injectors or the throttle body that needs to be cleaned. Once the fuel starts to flow and engine warms up, it’s much easier to start. However, it could also be an air filter, EGR valve or other components that causes this issue as well, which is why it’s best to have a professional mobile mechanic complete a car is hard to start inspection so they can pinpoint the source of this issue.

Read Full Q/A … : My car will not start. It is completely dead (zero power), is it my alternator?

Eric smoalih

I am a certified master technician with the National Institute for Automotive Service Excellence (ASE), and I have been working as an auto mechanic for over 15 years. I am passionate about my work, and I take great pride in helping people keep their cars running smoothly.