why does my BMW 3 Series E90/E91 (2005-2012) blower motor only work on one speed

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative terminal of the battery to ensure safety.

2. Remove the Blower Motor Resistor

• Locate the blower motor resistor, typically found near the blower motor under the dashboard on the passenger side.
• Remove the screws or clips securing the resistor and disconnect the electrical connector.
• Carefully extract the resistor from its mounting location.

3. Inspect and Replace

• Inspect the resistor for signs of damage, such as burnt contacts or melted plastic.
• If damaged, replace it with a new blower motor resistor. Ensure the new part matches the original specifications.
• Reinstall the new resistor in the reverse order of removal, securing it firmly.

4. Reinstall the Blower Motor (if necessary)

• If the blower motor was removed for testing, reinstall it by reversing the removal process.
• Ensure all connectors are properly seated and secured.

5. Reconnect Battery and Test

• Reconnect the negative terminal of the battery.
• Start the vehicle and test the blower motor at multiple speed settings to ensure proper operation.