I changed th alternator I’ve changed all the fuses and whenever I turn on the lights the battery drains dead and the windshield wi

When I start my car the battery level starts going down when I turn on the lights it really goes down and I turn on the windshield wipers and it did they stay on I've changed the alternator of all the fuses are good I need to know what to possibly be wrong with my truck

My car has 2748 miles.
My car has an automatic transmission.

Experienced mechanics share their insights in answering this question :
This may be a voltage regulator problem. As you may know the voltage regulator manages the amount of power the alternator supplies to the battery and other accessories. When this is not working correctly, the battery can be over charged or in some cases under charged.

How to Identify and Fix Common car Problems ?

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

If your Ford Expedition battery warning light comes on while driving, be sure to turn off your accessories, so the battery doesn`t drain further. The warning light usually means that the alternator isn`t working accurately meaning you`re operating solely on battery power.
A corroded or defective alternator diode will faultily continue charging the circuit even when the car off. This, in turn, will drain your car battery and cause the car not to start.
The most common reasons a Ford Expedition 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.
This indicates that the alternator is not working properly. What is this? The most common cause of this problem is an alternator failure. Alternators are responsible for charging batteries in cars and other vehicles, and when they fail they can cause all sorts of problems with your vehicle`s electrical system.
The battery light on your car dashboard signals a charging problem with your car battery. If the light turns and stays on, it might be that your alternator isn`t generating enough voltage to charge it. Common causes can be a broken alternator belt, damaged battery cells or a failed alternator.
What Causes a Car Battery to Keep Dying? Some of the most common reasons for a car battery to die repeatedly include loose or corroded battery connections, persistent electrical drains, charging problems, constantly demanding more power than the alternator can provide, and even extreme weather.
Probably, the most common symptom associated with a bad regulator is flickering, dimming, or pulsing lights. To be more specific, you may notice that the vehicle`s: Headlights fluctuate between bright and dim, without you doing anything. High beam isn`t working as expected.
The most common reason cars don`t start is a dead or faulty battery. Even though most cars run on gasoline, they all require electrical power to function. The starter that cranks your engine to start requires an electrical signal to fire. If something`s wrong with your battery, your car engine won`t turn over.
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. It can be hard to determine if you`re dealing with a battery or an alternator problem.
If your alternator is malfunctioning by over-charging your battery, disconnecting it may allow the alternator to provide an even higher voltage to the car electronics, and potentially damage those sensitive components.
Your vehicle is equipped with relays to help power your starter, lights, and other parts of its electrical system. Not all vehicles have alternator relays, but if your vehicle`s battery is dead and you`re not sure why, a malfunctioning or broken alternator relay could be the cause.
We recommend contacting a mobile mechanic since driving your vehicle to a dealership or auto repair shop with the battery light on isn`t safe or practical. A mobile mechanic can come to where you are and inspect your vehicle`s electrical system to check if you`ve got a bad alternator, charging problem, or so on.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

I changed th alternator I’ve changed all the fuses and whenever I turn on the lights the battery drains dead and the windshield wi
ANSWER : This may be a voltage regulator problem. As you may know the voltage regulator manages the amount of power the alternator supplies to the battery and other accessories. When this is not working correctly, the battery can be over charged or in some cases under charged.

Okay so when I turn my lights on at night my brake lights do not work, when I don’t have my lights on they work fine.
ANSWER : Hi there. Based on your inquiry, it’s highly probable that you have a damaged light switch or some electrical fault inside the turn signal relay. However, it’s also possible that the brake switch above the brake pedal could also be the source of your problem. Due to the fact that multiple electrical components might be causing this issue, it’s a smart idea to first have a professional mobile mechanic complete a brake lights are not working inspection, so they can determine what’s causing all of these issues and recommend the right repairs.

Battery drains quickly, New battery,Heavy drain, Replaced alternator , drain still there,goes away when bat. main 2 fuse is pulled
ANSWER : Hi there. It’s quite possible that you have one of two things causing the drain to the battery. First, you have a bad ground somewhere in the main relay or fuse box or an exposed wire somewhere that is not allowing the circuit to complete from the alternator to the battery. This can cause a battery draining issue as you’re describing, but it could also be one of multiple other electrical problems. The best way to pinpoint the exact source is to have a professional mobile mechanic come to your location and complete a battery will not hold a charge inspection.

I have Chrysler 300c. Battery light came on, changed battery and alternator but power still getting drained and battery light still comes on.
ANSWER : Hi, thanks for writing in. This may be a sign of a failing starter relay. The starter relay is a small unit near the starter that directs power to the starter from the battery. When this fails, it may cause a clicking sound and will not allow the starter to engage the flywheel when you turn the key. I would suggest having a professional from YourMechanic come to your home to diagnose your starting issue to determine the solution to get you back on the road.

Crank no start
ANSWER : Hey there, thanks for writing in about your 2003 Ford Explorer. It sounds to me like you either have no fuel or bad fuel at the injectors, or no spark to spark plugs. Try to narrow the problem to one of these possibilities. If you just got fuel before it dies, then you may have excessive water in the fuel. Take a fuel sample and let it settle in a cool place to see if water is in fuel. You already ruled out many components, but you have to double check and make sure that each test was done correctly. If you’d like further help with this, my recommendation would be to have a certified mechanic, such as one from YourMechanic, thoroughly diagnose the no start issue in person in order to have this properly resolved.

Battery light stays on and overnight battery drain. 2006 Land Rover LR3
ANSWER : Hello – this problem can be diagnosed by connecting an ammeter to the positive (red) battery cable, observe the current drain (likely less than 1 amp), then, one at a time, remove each fuse, check to see if the current drain has dropped to near 0, then reinsert the fuse. This process should identify the faulty circuit in most cases. The specific components on that circuit can then be checked for current drain problems. A professional mechanic, like YourMechanic, can come to your location, and perform this procedure for you, and identify, replace or repair the failing component.

Dome light turns on and off by itself while vehicle is turned off.
ANSWER : Hi there. Check the courtesy light switches on the doors to the vehicle. It seems that one or more switch may have a bad ground or a bad contact in the switch causing the courtesy light to come on while the engine is off and the key is out of the ignition with the doors shut. If you need further assistance with your courtesy light, then seek out a professional, such as one from Your Mechanic, to help you.

Battery light stays on and overnight battery drain. 2006 Land Rover LR3
ANSWER : Hi there – yes, something is going on here that’s draining your battery. Perhaps the pressure of the engine wash dislodged wiring which has shorted, or there was a chemical reaction to the cleaning solution that caused electrical damage in the alternator or voltage regulator. These componnents can be checked off of the vehicle. Vehicle wiring can be diagnosed by connecting an ammeter to the positive (red) battery cable, observe the current drain (likely less than 1 amp), then, one at a time, remove each fuse, check to see if the current drain has dropped to near 0, then reinsert the fuse. This process should identify the faulty circuit in most cases. The specific components on that circuit can then be checked for current drain problems. A professional mechanic, like YourMechanic, can come to your location, and perform this procedure for you, and replace/repair the failing component.