Parts specialist febi is offering a solution to a common problem which affects the interior heater fan motor on the popular Opel Vectra C, where the fan only works at full speed or does not work at all.

The problem also occurs on imported Vauxhall versions of the Vectra, as well as the Saab 9-3 and Opel Signum. The cause of the problem is often the water drains located below the windscreen becoming blocked causing water ingress. It may also be due to restricted cabin filter airflow a seized heater motor, or a faulty resistor relay or faulty heater motor resistor.

Febi say the problem may stem from more than one cause. If the heater motor is not working and the resistor fuse is blown, the technician should check the windscreen drains and unblock them as necessary. Then, replace the cabin filter and check if the heater motor turns freely and is free of corrosion before replacing the heater motor resistor.

If the heater fan motor only operates at full speed, febi recommends to check the relay K4 that controls fan speeds 1, 2, and 3. This is situated near the heater motor. It is necessary to remove the glovebox in order to access it.

The K4 relay controls the heater motor fan speed settings 1, 2, and 3, while setting 4 is controlled by the K5 relay. The relay acts as a switch to provide power to the relevant fan speed setting. If the K4 relay is no longer working, it will not be possible for the motor to work at the speed settings 1, 2, and 3 and the technician should replace parts as necessary.

The resistor for the blower is febi part no. 108099 and is available from febi stockists.