The cooling system fans are driven by two permanent magnet DC motors

The engine management system controller controls the operation of the fans.

The engine cooling system fan motors do not require maintenance.

If they fail, replace them with new ones.

To check the serviceability of the electric motors, use the data in the table. 1.

Fig. 1. Wiring diagram of the electric motors of the cooling system fans: 1 - right electric motor of the engine cooling system fan; 2 - additional relay; 3 - fuse; 4 - additional resistor; 5 - relay for turning on the right electric motor; 6 - left electric motor of the engine cooling system fan; 7 - relay for turning on the left electric motor; A - to the negative terminal of the battery; B - to the main relay; C - to the "+" terminal of the battery

Data for checking the electric motors of the fans of the engine cooling system

Nominal speed of rotation of the shaft with the electric motor load by the impeller, min -1 - 2600-2800

Current consumption at the specified load and speed, A, no more than 25

The controller controls the relay for turning on the electric fans of the engine cooling system.

The electric fans turn on and off depending on the engine temperature.

Electric circuit of the cooling system fans

The diagram in Figure 2 is given for the ME17.9.71 Niva Chevrolet EURO-5 controller

The electric fans operate in two modes - with maximum performance (parallel connection) and with reduced performance (sequential connection) (Fig. 2).

Reduced performance of electric fans is switched on when the coolant temperature is above 99° C, and also if there are DTOZH fault codes in the controller memory or when the air conditioner is running.

Electric fans are switched on sequentially via an additional relay.

The additional relay is controlled from the controller contact "X1/41".

Reduced performance of electric fans is switched off after the coolant temperature drops below 94° C.

Maximum performance of electric fans is switched on when the coolant temperature is above 101° C, and also at high refrigerant pressure in the line, both with the air conditioner running and not running.

Electric fans are switched on in parallel via an additional relay, the right electric fan relay and the electric fan relay left.

The additional relay is controlled from the "X1/41" contact of the controller.

The right electric fan relay and the left electric fan relay are controlled from the "X1/52" contact of the controller.

The maximum performance of the electric fans is switched off after the coolant temperature drops below 95° C.

If there are active DTOZH fault codes, the electric fans of the cooling system operate until the codes are cleared or the engine is stopped.

Replacing the electric motor

You will need a "10" key.

Disconnect the wire from the "minus" terminal of the battery.

Remove the electric fans together with the casing.

Replacing the electric motor

Unscrew the nut and remove the impeller.

Replacing the electric motor

Remove the pin from the motor shaft.

Replacing the electric motor

Unscrew the three nuts securing the electric motor to the casing.

Replacing the electric motor

Remove the wire holder.

Replacing the electric motor

Remove the electric motor.

Install the electric motor and impeller in the reverse order of removal.