Volvo S40/V40 blower motor controller replacement

Is your Volvo air conditioning system having issues due to a bad blower motor controller? Learn how to fix the problem by replacing the blower motor controller of your Volvo.

Like any other car, your Volvo uses a blower motor to push the air into the cabin. A control unit regulates the blower motor operation. In the past, this was a simple resistor with several available speeds.

Modern cars have a climate control system that regulates blower motor operation using a speed controller unit. This system works codependent on the engine operation, with the engine control module considering the heating and air conditioning system.

As a result, the blower motor speed varies according to engine speed and various other inputs. This is done by a speed controller, which converts a baseline signal according to inputs from the electronic control assembly.

Common symptoms

If the blower speed controller starts failing or fails, it will cause issues related to the control and operation of the heating and air conditioning system. In some cases, the blower motor will not work at all.

Other symptoms include occasional sudden motor speed changes without the driver’s input or the inability to regulate the blower speed. Luckily, replacing the controller is an easy job.

Replacing the controller

1. The controller is placed under the dashboard, behind the glove box. Working inside the passenger footwell, locate and remove the thick fabric cover at the bottom side of the dashboard (see image below). Two Phillips-head screws hold it in place.
2. Look up the opening to locate the controller, as in the image below. It has a connector (item 1) and two Phillips-head screws (item 2) that hold it in place.
3. Press the tabs on the connector to set it free, move it out of the way, and then remove both screws.
4. A metal ledge at the bottom of the glove box assembly prevents controller removal. Disassembling this ledge would require removing several dashboard components. To avoid this, bend the part of the ledge (item 3 on the previous image) that is in the way using pliers. It is not a structural component, and this will not affect safety.
5. Pull out the controller and reinstall the new unit. As much as possible, bend the metal ledge in the original shape.
6. Reinstall the remaining parts in reverse order.

We hope you find the Volvo S40/V40 blower motor controller replacement guide helpful. Check these troubleshooting and repair guides for more help on your Volvo.