As a veteran with over 20 years of experience in auto repair, I believe there are several common reasons why the BMW 1 Series air conditioning won't turn off. First, check the control button—it might be stuck in a certain position or have worn internal contacts, preventing the signal from being sent. This is quite common, especially in frequently used vehicles. Second, there could be electrical issues, such as a blown fuse or a failed relay, which cuts off the current and prevents the system from shutting down. I've repaired many such cases, and you can simply open the fuse box to replace them yourself. Third, the air conditioning control module might be faulty. This is a core component, and once it malfunctions, it can force the system to keep running, requiring professional diagnostic tools to read the error codes. Fourth, sensor failures, such as a malfunctioning temperature sensor, can cause the system to misjudge the need to keep working. Fifth, the fan or compressor might be mechanically stuck and unable to shut off—this is rare but dangerous. For safety, if the AC won't turn off, don't force it. Park immediately to check for unusual fan noises or overheating to prevent the risk of spontaneous combustion, and seek professional help from a reputable repair shop as soon as possible. Regular maintenance, such as cleaning the AC air intake, can help reduce such issues.
