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Can a stuck relay drain a car battery?

A failed ECM power relay can also cause a battery drain or dead battery. If the relay shorts it can leave power on to the computer, even when the vehicle is turned off. This will place a parasitic drain on the battery, which will eventually cause it to go dead.


How can I tell if my alternator is draining my battery?


How do I find a short drain on my car battery?


Why does my car keep dying with a new battery and 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.


Can a bad alternator cause battery drain?

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.


Can a bad relay cause battery drain?

Bad ignition relay The ignition relay is essentially an electrical device that works as a switch for the power to the ignition system. Its job is to make sure electricity flows from the battery to the different components that need power. A bad relay will drain your battery and make it difficult to start the ignition.


Will a bad starter relay drain your battery?

The starter relay not only completes the electrical circuit, but it also boosts the battery’s current. If your starter relay has gone bad, the electrical signal will never make it from the battery to the starter motor.

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What causes parasitic battery drain?

Electrical components such as computers, the radio, the internal clock, alarm, power mirrors and more will create a slight draw known as parasitic drain. However, when the amount of electricity pulled goes beyond the normal range, it becomes a problem that may affect your battery’s performance and service life.


Can an alternator diode drain a battery?

Bad Diode. A malfunctioning diode in the alternator can create a parasitic drain on a car’s battery. Diodes should allow current to pass in only one direction, but a bad diode will keep the charging circuit open even when the engine in not running, allowing the battery to go dead. This often happens overnight.


How do you check for a parasitic draw on a car battery?

Pull the negative off the battery. Put the test light between the post and the ground wire. If the light illuminates, you have a draw. Use the fuse pull method to find the draw; when the light goes out, you found the draw.