Subaru Legacy electrical blackout issue with unknown cause after one year of use on Subaru Legacy

Some Subaru Legacy owners report experiencing electrical blackout issues after one year of use, often linked to battery drain when the car remains idle for a few days, potentially due to a faulty battery or excessive power drain from an underlying electrical problem. Additionally, problems with the alternator, generator, or regulator have been noted, which can lead to failures in the electrical system. Owners who have installed aftermarket security systems also report malfunctions, such as warning lights activating and screens not functioning properly, possibly interfering with the electrical system. Furthermore, issues with the Starlink system draining the battery due to outdated network connections have been identified as a contributing factor. In some older models, such as the 1999 Legacy, the speedometer head has been recognized as a potential source of electrical problems. To address these issues, it is advisable for owners to check the battery and alternator for faults, verify any recent modifications, and consider the impact of the Starlink system. If problems persist, consulting a professional mechanic or dealership for a thorough diagnosis is recommended.