What is the reason for the low air volume of the BMW 5 Series blower?

[RobertRose]

The reason for the low air volume of the BMW 5 Series blower is blower damage. Blower: The blower is a fan in the air conditioning system. The blower draws air from inside or outside the vehicle through the rotation of the impeller and, under the action of centrifugal force, directs it into the air conditioning unit. By adjusting the input voltage of the blower, the blower speed is changed, thereby altering the air volume. Solution for blower damage: After disconnecting the power, open the rear cover of the blower and add a few drops of lubricating oil to the bearing sleeves at both ends of the rotor. While adding oil, rotate the blades until the fan operates smoothly, and the blower issue will be resolved.

[DiRicardo]

I've been driving a BMW 5 Series for years. Common reasons for weak blower airflow include aging and wear of the blower motor leading to reduced speed, which is quite common; accumulated dust in the cabin air filter blocking the air intake and restricting airflow; faulty resistor module causing irregular speed adjustment; blown fuse directly cutting off power supply; loose or corroded wiring connections affecting current transmission. Problems with the control switch may also cause operational issues. The impact is significant—summer heat becomes unbearable inside the car, and insufficient warm air in winter increases the risk of catching a cold. I recommend owners first check the air filter and replace it if dirty, as it’s simple and inexpensive. If that doesn’t help, visit a professional shop to test the motor and resistor—don’t delay, especially before long drives where fatigue can set in more easily. Regular maintenance and cleaning the filter can prevent issues. BMW’s air conditioning system is quite sophisticated, so DIY repairs carry risks—it’s best to use genuine parts for durability.

[LucilleFitz]

As a car enthusiast, a weak airflow in the BMW 5 Series blower may be caused by worn carbon brushes in the blower motor reducing efficiency; damaged resistors preventing graded control of fan speed; faulty control module signals; blown fuses protecting the circuit; clogged or dust-accumulated air intake ducts. Voltage instability can also interfere. Using a multimeter to measure resistance values can help diagnose the issue. It's recommended to start with simple checks, such as inspecting and promptly replacing dirty filters. Replacing a faulty resistor is not costly, but wiring issues require professional handling. Weak airflow affects cabin air circulation, especially causing breathing discomfort during traffic jams. Regular cleaning of the engine compartment to reduce dust intrusion can extend component lifespan and prevent sudden failures.

[EmersynDella]

I commute in a BMW 5 Series, and when the air volume is low, the car feels stuffy. Usually, it's due to a clogged filter or a faulty motor. Try simply replacing the filter first; if that doesn't work, take it to a repair shop to check the fuses and wiring. Don't wait—it affects driving comfort and distracts attention. Safety first, addressing it promptly can save hassle.