Crown Vic Alternator Not Charging: Where Is The Issue

Battery not charging is a common problem with the Crown Vic, and a replacement alternator is the usual solution. But what if the Crown Vic alternator is not charging even after replacing it?

Have you noticed the Crown Victoria alternator not charging the battery? If yes, then there can be various potential reasons for it. For instance, the belt connecting the alternator and crankshaft can be damaged with time; hence, the alternator does not work and cannot supply power to the battery.

There are various wire which connects the alternator and wire. The cables can get damaged, or rodents can chew them, so the alternator fails to provide power to a Crown Victoria battery.


Crown Vic Alternator Not Charging: Where Is The Issue

What Does an Alternator Do?

The engine of a car can produce mechanical energy but not electrical energy. We need a power source to produce electricity and power various car accessories like headlamps, tail lights, and other electrical components. This is where alternators come in. An alternator is an electrical generator used in cars to charge batteries and power electronic components when the engine is in running condition.

The alternator has a stator and rotor. The stator is the stationary part, and the rotor is the rotating component in the alternator. The car alternator works only when the engine is in running condition because the rotor needs an engine belt for spinning.

The rotor spin inside the stator winding and produces alternating current. This alternating current is transferred to the direct current by the rectifier and then supplied to the battery.

If the battery is overcharged or undercharged, it can create serious problems. A voltage regulator provides power from the alternator to the battery and controls the energy to provide steady power to the battery.

Checking The Voltages To Diagnose The Problem Solutions To Likely Problem

If the battery warning light comes on while driving, then there is some problem with the battery. It indicates that the alternator is no longer charging it and you will send up with a dead battery. Most people think that this might be an issue with the car’s batteries. But no, sometimes, the problem can be with a bad alternator. So, inspect the alternator thoroughly.

First, check the voltage of the battery cables connected to the alternator by using a voltmeter on the positive battery terminal. The wire must be 12 volts all the time. You need to look for the fuse box if the wire does not have 12 volts.

There are various car models in which the alternator depends on a specific fuse. The fuse can blow away because of insufficient power or time. So check your car manual to ensure there is a fuse for the alternator and if it’s there, then check it.

The green and red wire should be 2 volts when the engine is not running. These wires should be above 12 volts when the engine is running.

There are some issues if you find 0 volts on the green and red wires. The wire can most probably be grounded if the dashboard light is on. There can be a problem with the connector pin if the dashboard light never switches on.

If you find the voltages are good enough in green and red wire, you need to check the black and white wire. When the engine is in working condition, these wires must be in 6 volts. You should not forget to measure the large output wire voltage. It must be between 13.75 to 14.75 voltage when the engine is running condition.

Check the battery voltage when the engine is running. If it is between 13.75 to 14.75 volts, then a car’s charging system is absolutely working.


Crown Vic Alternator Not Charging: Where Is The Issue

Solutions To Likely Problem

#1. Grounding a Wire

The ground wire of the alternator runs from the engine block to the battery. If a power surge takes place in your car, then it can severely damage the car’s alternator and other components. But suppose the ground wire is in good condition.

In that case, it will draw excess electricity at the time of power surge and move it away from the alternator and other accessories and prevent it from damaging.

But the ground cable can wear and tear with time, so the alternator will not function properly.

A few symptoms of the bad ground wire are as follows.

  • Vehicle may not pass voltage test.
  • The car battery may stop recharging.
  • Headlights may start flickering.

#2. Fusible Link is Blown

Take a voltmeter and check the voltage of the wire in the alternator. But remember that time the engine should be in off condition. The fusible link is not blown if the voltage is between 13.5 to 14.5 volts. But if the voltage is below 13.5 volts, it’s a sign that the fusible link has blown away.

Now check the green and red wires plugged inside the voltage regulator. It should be within 3-11 volts with the ignition switch on. If the voltage is not within this range, check the circuit’s fuse. The yellow and white wire going to the same plug should be within 13.5 to 14.5 voltage, i.e., battery voltage, all time.

#3. Check For Wire Between Alternator and Battery

The alternator is connected to the car’s battery by two wires, i.e., red and black. The red or positive wire goes directly from the alternator to the battery, and the negative or black wire goes from the alternator to the car chassis and battery.

You need to check the wire from the alternator to the battery. Take a multimeter and measure its voltage. The wire works well if it’s 13 volts and above. Sometimes mouse can chew the wire, and hence it will lose connection. The wires can also damage with time, and hence they will lose connection from the alternator to the battery. You need to replace the wire as soon as possible.


Crown Vic Alternator Not Charging: Where Is The Issue

#4. Alternator Might Be Bad

There may be problems with the alternator, for which it cannot charge the battery when the engine is running. For instance, a belt connects the engine to the alternator. The belt is always in contestant tension and friction. Hence it wears with time and causes your car alternator to malfunction. The wires or copper windings inside the alternator can burn or wear out with time.

The alternator is designed to work between 13.5 to 14.5 volts. But when it malfunctions, the voltage reduces and cannot charge the battery. Hence the battery light gets illuminated on the dashboard.

Frequently Asked Questions

#1. Can a fuse cause alternator not to charge?

There are various car models where the alternator depends on the fuse for operation. But the fuse can blow away due to unexpected voltage rise or wear with time. When the fuse blows, the alternator cannot charge the battery. Hence the charging warning light or check engine light illuminates the dashboard.

#2. What would cause a good alternator not to charge?

There are several possible reasons why an alternator can not charge the battery. For instance, the alternator wires may damage with time and for which it loses connection with the battery.

The fuse can blow away because of excessive voltage, so the alternator will not function.

So, check the cables and fuse from time to time to ensure they are in good condition.

#3. How do you test an alternator not charging

  • You need to buy a multimeter to measure the voltage and other electrical properties like current and resistance while checking the car alternator. A voltmeter may also help to measure the voltage.
  • You need first to check the battery. Switch off the car and connect the voltmeter to the battery. If the battery measures 12.2 volts, it has a good amount of juice for starting the alternator. If the battery does not have enough charge, then charge the battery and then retest the voltage.
  • Start the car and make the engine revolute at 2000 rpm.
  • Now test the battery again with the voltmeter. If the battery voltage varies between 13.5 and 14.5 volts, then the alternator is in good condition. But if the voltage starts to reduce below 13.5 volts, there is a problem with the alternator.


Crown Vic Alternator Not Charging: Where Is The Issue

#4. Why is my battery light on, but the alternator is charging

There is a belt that connects the alternator o the crankshaft. But the belt can be broken with time. Hence the alternator will not be able to charge the battery. The car battery will illuminate n the dashboard to indicate this problem.

Wrap Up

The alternator is an essential component of the car. It helps in providing power to the car battery. But it can malfunction with time, as the wires get damaged, or the fuse can blow away. Please check the wires and their voltage from time to ensure they are in healthy condition. Thank you for reading this article.

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Sean Mendez

Hi, I am Sean, a self-confessed petrolhead. I live in Boise, Idaho with a busy family of four and our energetic Labrador retriever. Thank you for visiting my website. You can find my email on the contact page.

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