Is the Circuit the Cause of BMW 320 Rear Turn Signal Failure?

[EmeryMarie]

BMW 320 rear turn signal failure is mainly caused by three aspects: the bulb, the headlight control module, and related wiring. 1. If this problem occurs after washing the car, it is generally due to water immersion in the wiring harness or moisture in the headlight module. 2. If the light fails after driving on uneven roads with excessive vehicle vibration, we should suspect whether the related wiring harness connectors have become loose. 3. If the headlight fails and occasionally recovers on its own, this is usually an issue with the headlight control module or related wiring. BMW has previously issued recalls due to defective socket connectors in the left and right taillights, as these connectors can develop increased resistance after prolonged use. Solution: First, check if the bulb is damaged. Then, if only one side fails, swap the left and right headlight modules to see if the failure transfers. If it does, the issue is likely with the module itself. If not, carefully inspect the related wiring harness and connectors, and also clean the headlight module. If both sides fail, this is generally not a problem with the headlight module itself but should focus on the higher-level footwell module and the bus system.