A thermal switch is installed in the right radiator tank, which turns on the engine cooling fan if the coolant flowing through this tank has a temperature above the required temperature. It also turns off the fan if the coolant temperature drops below a certain value. At the switch-on temperature, the contact in the thermal relay closes the electrical circuit of the engine cooling fan, and it starts to work.
Be careful when working in the engine compartment: when the ignition is off and the engine is hot, the fan may turn on by itself. Therefore, when the engine is hot, do not put your hands in the area of the engine cooling fan!
Note. Recommendation: In order to check if the engine cooling fan actually starts on a hot engine, you need to do the following: with the engine already warm, idling, monitor the coolant temperature reading. The fan must turn on before the instrument pointer (depending on modification) enters the shaded area. In this case, the overheating control lamp should not light up, otherwise there is a high probability that the thermal relay is faulty.
Malfunctions of the fan of the engine cooling system
A faulty engine cooling fan can cause the coolant temperature to be too high; this happens when the engine is idling for a long time or when driving in the mountains.
A faulty fan doesn't mean your trip is over:
- After the engine has cooled down, you can drive to the nearest car repair shop at medium engine speeds and a constant, fairly high speed. At the same time, monitor the temperature of the coolant and the overheating warning lamp.
- Idling and slow driving in this case are dangerous for the engine, since sufficient air does not pass through the radiator plates for cooling.
Troubleshooting
1. Disconnect the double plug of the thermostat.
2. Connect both contacts in one of the halves of the double plug with a wire.
3. If the fan is running, then the thermostat is faulty.
4. To continue the trip, secure the previously inserted piece of wire that closes the contacts.
5. To keep the free-hanging wire from dangling and to avoid a short circuit, wrap the double plug block with adhesive tape.
Removing the engine cooling fan
Motor type «WITH», as well as on some engines such as «F» a freely rotating fan is installed, and its motor can be riveted to the fan holder (2). The fan holder is screwed to the left and right of the radiator tanks (1).
A more powerful diesel fan or a 16-valve engine has a better flat motor that rotates the fan impeller in the duct.
1. Disconnect the terminal of the pass from the battery and disconnect the plug-in connection of the wire of the thermal relay and the fan of the engine cooling system.
2. Disconnect the wire from the fan mount holder.
3. For removal unscrew two bolts of fastening of the engine of the fan.
4. Remove the fan motor together with the holder from the radiator.
5. If the fan motor is riveted to the holder, drill out the rivets.
6. Fix the fan pulley and unscrew the central nut.
Attention! Attention: left-hand thread!
7. Remove the fan pulley.
8. When installing, use bolts instead of rivets to connect the fan motor to the holder, while treating them with an agent against self-unscrewing.
One of the ways to determine the malfunction, if there is a suspicion of a fan motor, then disconnect the plug connection (2) thermostat on the radiator and close both sockets of the plug with wire or a paper clip. The fan must be running.
The 16-valve engine has an additional electric coolant pump (shown by arrow) in the cooling system, which, after turning off the ignition, continues to drive the coolant through the cooling system for about 5 minutes. On an overheated engine, the engine cooling fan also turns on.