The most common reason for a BMW 325i battery light flashing is a low battery voltage. Check the battery voltage using a multimeter. If the voltage is below 12.4 volts, the battery needs to be charged or replaced.
Alternator Problems:
If the battery voltage is normal, the next thing to check is the alternator. The alternator is responsible for charging the battery. If the alternator is not working properly, it cannot provide enough power to the battery, which can cause the battery light to flash.
Wiring Issues:
A flashing battery light can be caused by loose or corroded wiring. Check all the wiring connections between the battery, alternator, and starter motor. Make sure the wires are tight and free from corrosion.
Faulty Voltage Regulator:
The voltage regulator controls the amount of voltage that is supplied to the battery. If the voltage regulator is faulty, it can cause the battery light to flash.
Electrical Overloads:
If you have too many electrical devices turned on in your car, it can overload the electrical system and cause the battery light to flash. Try turning off some of the electrical devices to see if the battery light turns off.
If you have checked all of these things and the battery light is still flashing, you should take your car to a qualified mechanic for further diagnosis.
