The electric motor has three rotation speeds. Low frequencies are provided by an additional resistor 5 (figure 130), fixed with a screw on the left side of the heater radiator casing. The resistor has two spirals - one with a resistance of 0.23 Ohm and the second - 0.82 Ohm. When both spirals are included in the electric motor power supply circuit, the first fan speed is provided, if the spiral with a resistance of 0.23 Ohm is included - the second speed. When the electric motor is turned on without a resistor, the fan rotor rotates at a maximum third speed (4000 rpm).
Figure 130. Wiring diagram for the heater electric motor and rear window heating element:
1 - mounting block; 2 - rear window heating relay; 3 - ignition switch; 4 - heater motor switch; 5 - additional resistor; 6 - heater electric motor; 7 - Rear window heating switch; 8 - Instrument cluster with rear window heating indicator lamp; 9 - rear window heating element.
If the electric motor operates intermittently, it is necessary to check the power supply wires and their connections, the serviceability of the heater switch, and also clean the electric motor collector with fine-grained sandpaper and check the condition of its brushes. To clean the collector, there is no need to remove the electric motor from the car. It is enough to remove only the cover with the brush holder, having unscrewed the two fastening screws and having previously removed the protective casing from the electric motor.