The design of the electric motor of the fan of the heating and ventilation system

The car is equipped with a heater fan electric motor with excitation from permanent magnets.

To obtain different speed values, an additional resistor is installed in the power supply circuit of the heater electric motor. It has three coils and a fuse. When current passes through all three spirals, the 1st speed of rotation of the heater fan is provided, through two spirals - the 2nd speed, through one - the 3rd speed. When the heater motor is turned on without an additional resistor, the fan motor armature rotates at the maximum 4th speed. If the heater motor fails, replace it with a new one. The only possible repair of the heater motor is to clean the collector.