The car is equipped with a heater fan motor with permanent magnet excitation

Data for checking the electric motor are given in the table

In order to obtain different speeds, an additional resistor is installed in the power supply circuit of the electric motor.

The resistor has three coils and a fuse.

When the current passes through all three spirals, the 1st speed of rotation of the heater fan is provided, if the current passes through two spirals - the 2nd speed, through one - the 3rd speed.

When the motor is turned on without an additional resistor, the fan motor armature rotates at maximum speed 4 (3000 min -1).

If the motor fails, replace it with a new one. The only possible repair of the electric motor is to clean the collector.

Fig. 1. Scheme of switching on the electric motor of the heater fan and the rear window heating element: 1 - ignition switch; 2 - mounting block; 3 - heater motor switch; 4 - additional resistor; 5 - heater electric motor; 6 - rear window heating element; 7 - switch for heating the rear window with a control lamp; A - to power supplies; K6 - additional relay; K7 - rear window heating relay

Data for checking the heater fan motor:

Shaft rotation frequency when the electric motor is loaded with an impeller at a voltage of 12 V and a temperature of (25 + 10) ° С 3000 min -1

Consumed current at the specified load and speed, A, no more than 18

Removing and installing heater fan motor

You will need a screwdriver.

Disconnect the wire from the negative terminal of the battery.

Remove the glove box.

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Disconnect the wiring harness from the motor.

Niva Chevrolet heater motor replacement

Disconnect the air supply hose.

Niva Chevrolet heater motor replacement

Remove the three screws securing the electric heater fan

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Remove the electric fan assembly with the impeller.

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Remove the spring washer

Niva Chevrolet heater motor replacement

Remove the impeller.

Install the impeller on the electric motor and the electric fan on the car in the reverse order of removal

Removing and installing an additional heater fan resistor

You will need a screwdriver.

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Disconnect the wire from the negative terminal of the battery.

Disconnect the wiring harness connector from the heater.

Niva Chevrolet heater motor replacement

Remove the screw securing the additional resistor and remove the resistor

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Install the resistor in the reverse order of removal

Possible malfunctions of the heater fan motor, their causes and remedies

Cause of malfunction Remedy

Electric motor not working

Wires damaged or wire connections oxidized - Check and repair connections. Replace damaged wires

Fuse F18 blown in fuse box - Replace fuse

Heater switch damaged - no voltage applied to switch output terminals - Check switch, replace if necessary

Hanging or worn brushes of the electric motor, breakage in the armature winding or pollution of the collector - Check the electric motor, repair or replace

Short circuit to ground of the armature winding - when the motor is turned on, the fuse burns out - Replace the motor

Electric motor only runs at one speed

Wires damaged or wire connections oxidized - Check and repair connections. Replace damaged wires

Heater switch damaged - Check switch, replace if necessary

Auxiliary resistor burned out - Replace additional resistor

Motor armature rotates slowly

Dirty or oxidized commutator, worn brushes - Clean commutator, replace brushes

Turn-to-turn short circuit in armature winding - Replace motor

Archor shaft sticking in bearings - Replace motor