Electric motors of the heater fans (VAZ-2108)

Electric motor type 45.3730, with excitation from permanent magnets. Its connection diagram is shown in Figure 152. An additional resistor 5 is used to obtain different rotation speeds. It is 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 with 0.82 Ohm. When both spirals are included in the electric motor power supply circuit, 1st speed is provided (the smallest) rotation of the fan, if the spiral with a resistance of 0.23 Ohm is turned on - 2nd speed. When turning on the electric motor without a resistor, the fan rotor rotates at the maximum 3rd speed (4000 rpm).

Figure 152. Wiring diagram for the heater electric motor and rear window heating element: 1 - mounting block (fragment); 2 - rear window heating relay; 3 - ignition switch (fragment); 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 (fragment); 9 - rear window heating element

It is recommended to replace a faulty electric motor with a new one. The only possible repair is cleaning the collector. There is no need to remove the electric motor from the car for this. It is enough to remove the protective cap, and then the cover with the brush holder by unscrewing the two mounting screws.

Brief technical characteristics of the electric motor:

Shaft rotation speed under rotor load (or torque of 0.022 kgf·m) at 12 V and temperature of (25±10)°C, rpm — 4100±200
Current consumption at the specified load and rotation speed, A, no more than - 14

Possible malfunctions of the heater fan electric motor, their causes and methods of elimination are given in Table 26.