If the electric motor does not work or its armature rotates slowly, you should check the operation of the heater motor switch. The switch is removed from the socket by prying it with a screwdriver blade, and the wires are connected directly without a switch. After confirming the malfunction, the switch is replaced.
If everything is in order with the switch, and the electric motor does not work, it must be removed and figured out what is the cause of the failure. The following possible faults are known:
- freezing or wear of the motor brushes, a break in the armature winding or oxidation of the collector;
- short to ground of the armature winding. This defect is confirmed by the instant blown fuse when the heater is turned on;
- grabbing the armature shaft in the bearings.
In order to remove the heater motor, it is necessary to perform several auxiliary operations:
- disconnect the ground wires from the battery;
- remove and remove the four spring clips and, having disconnected the wires, remove the fan shroud from the radiator;
- remove the two spring clips and remove the electric motor from the fan casing.
If necessary, clean the armature collector from oxidation, it is necessary to unscrew the screws securing the cover and remove it, as well as remove the lock washer from the armature shaft and remove the armature from the housing. The collector is cleaned with a fine-grained sandpaper, blown with compressed air and lubricated with a thin layer of technical petroleum jelly. The electric motor and heater are assembled in the reverse order of disassembly.