7.8.1. Features of the device

Fig. 7.29. Scheme of turning on of the electric motor of the fan of a heater and element of heating of back glass: 1 – assembly block; 2 – ignition switch; 3 – relay of unloading of the switch of ignition; 4 – heater electric motor switch; 5 – additional resistor; 6 – heater electric motor; 7 – the switch of heating of back glass with a control lamp of inclusion; 8 – element of heating of back glass; K7 – the relay of inclusion of heating of back glass

The electric motor of 45.3730 type, with excitement from permanent magnets. The scheme of turning on of the electric motor is shown in fig. 7.29.
For obtaining small frequency of rotation the additional resistor serves. It is fixed by the screw on the left side of a heater radiator casing. The resistor has two spirals — with a one resistance of 0,23 Ohms and the second – 0,82 Ohms. At inclusion in a power-supply circuit of the electric motor of both spirals the 1st speed of rotation of the fan is provided if the spiral with a resistance of 0,23 Ohms – the 2nd speed is included. At turning on of the electric motor without resistor the rotor of the fan rotates with the maximum 3rd speed (4100 min.-1).
The faulty electric motor is recommended to be replaced new. The unique repair — cleaning of a collector. For this purpose there is no need to remove the electric motor from the car. It is enough to remove a water reflective guard, the protection cover of the electric motor, and then an electric motor cover with the brush holder.
Data for check of the electric motor
Frequency of rotation of a shaft at electric motor loading a krylchatka at a voltage of 12 V and temperature of 25±10 °C, min.-1        4100±200
The consumed current at the specified loading and frequency of rotation, And,       no more than 14