Why is my alternator draining my car battery?
Since the alternator isn’t generating vehicle electricity, the problem component pulls from the battery, slowly draining it overnight until your vehicle won’t start.
Why does my Mercedes-Benz battery keep draining?
You try to start your Mercedes-Benz and the car is either completely dead or this happens: Battery drains happen when electronic equipment (consumer units) are constantly drawing current from the battery while the car is parked. One simple example is when lights are left on overnight. But it’s not always as simple as that.
What does it mean when battery drain is slow?
A slow battery drain when everything is off is called a parasitic power loss. This happens when something – a glovebox light, an amplifier, any electrical component – is pulling power from the battery when it shouldn’t.
Can a battery run down with no alternator?
An alternator that’s not providing enough power can allow a battery to run down. According to Prestolite electric, an alternator producing less than 13.8 volts of power at idle is not producing enough current to charge the battery fully and needs to be replaced.
Can a bad alternator drain a car battery?
A car alternator recharges the battery and powers certain electrical systems like lights, radio, air-conditioning, and automatic windows. If your alternator has a bad diode, your battery can drain. The bad alternator diode can cause the circuit to charge even when the engine is shut off, and you end up in the morning with a car that won’t start.
What causes a car battery to drain in the morning?
If your alternator has a bad diode, your battery can drain. The bad alternator diode can cause the circuit to charge even when the engine is shut off, and you end up in the morning with a car that won’t start. 5. Extreme Temperature
Why is the battery draining on my Mercedes medic?
If the car is left parked in high pedestrian traffic areas this could be a problem. It may cause the battery to drain within a couple of days in some models. Try to turn off the proximity key function in your car by looking up the instructions on the owner’s manual.
What does it mean when your alternator drain is within range?
Reading within range: If your reading is within range, you’re probably dealing with a faulty charging system or battery. To do a quick alternator drain power check using your digital multimeter, go to the section Bad Alternator Diode Test below.
How to find the cause of parasitic battery drain?
Luckily, you can usually find the cause of a parasitic draw yourself. Start by connecting a digital multimeter to the negative battery terminal of your vehicle. Then, remove the fuses one at a time while watching for changes in the multimeter’s reading.
Why does my OnStar battery drain so much?
Community Answer In older vehicles running analog Onstar, the system will drain the battery because it is constantly looking for a signal. Onstar no longer offers an analog signal, only digital.
What does it mean when your battery drains overnight?
Why the Battery Drains Overnight A slow battery drain when everything is off is called a parasitic power loss. This happens when something – a glovebox light, an amplifier, any electrical component – is pulling power from the battery when it shouldn’t.
Luckily, you can usually find the cause of a parasitic draw yourself. Start by connecting a digital multimeter to the negative battery terminal of your vehicle. Then, remove the fuses one at a time while watching for changes in the multimeter’s reading.
Community Answer In older vehicles running analog Onstar, the system will drain the battery because it is constantly looking for a signal. Onstar no longer offers an analog signal, only digital.
How can I find out if my battery is draining?
Replace the fuse and disconnect each lamp, heater, or electrical device one at a time. Flip all of the switches that correspond to the components as well. Watch for the reading on the multimeter to drop to find out which component is causing the drain. For instance, say the offending fuse controls the power antenna as well as the radio.
How to get rid of negative battery drain?
Remove the negative battery cable from the negative battery terminal. Find the negative cable, which will be marked with a minus sign (-) and may have a black cover over it. Remove the cover, if applicable, and use a wrench to unbolt the negative cable from the terminal.