BMW X3 won't start after heavy rain, possible starter issue despite battery and relay replacement on BMW X3

Some BMW X3 owners report experiencing starting issues after heavy rain, which may be attributed to several factors despite having replaced the battery and relay. Moisture can seep into the starter, leading to malfunctions that prevent proper engagement during starting attempts. Additionally, a faulty ignition switch affected by moisture may hinder the vehicle from starting. Corroded electrical connections, particularly those related to the starter, can disrupt the starting process due to water exposure. Some owners also find that excessive moisture damages wiring connected to the starter, causing connectivity problems. Furthermore, grounding issues caused by water can impact the electrical system, preventing the starter from functioning correctly. To resolve these issues, it is advisable for owners to inspect the starter for moisture, check the ignition system, examine electrical connections for corrosion, evaluate wiring for damage, and verify that grounding points are secure and free from corrosion.