my BMW 3 Series E90/E91 won’t blow air out of the vents, what should I check?

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the vehicle battery to ensure safety while working on the electrical components.

2. Cabin Air Filter Replacement

• Tools Required: Screwdriver, replacement cabin air filter
• Remove the glove compartment by unscrewing the screws and gently pulling it down.
• Locate the cabin air filter housing and remove the cover.
• Take out the old cabin air filter and install the new one, ensuring it is oriented correctly.
• Reassemble the glove compartment.

3. Blower Motor Inspection

• Tools Required: Multimeter, power source (e.g., jumper cables)
• Locate the blower motor, usually under the dashboard on the passenger side.
• Disconnect the blower motor wiring harness.
• Use a multimeter to test for voltage at the connector while the HVAC is set to high. If voltage is present, the blower motor is faulty; replace it.

4. Climate Control Module Check

• Tools Required: OBD-II scanner
• Reconnect the battery and turn on the ignition.
• Use the OBD-II scanner to check for any error codes related to the climate control system.
• If there are any codes, refer to a repair manual for specific troubleshooting steps related to those codes.

5. Fuse Inspection

• Tools Required: Fuse puller or pliers
• Locate the fuse box; refer to the owner's manual for the exact location.
• Inspect the fuses related to the HVAC system and replace any that are blown.