Table of contents: Troubleshooting ↓ Removal the radiator fan ↓
If the thermostat is stuck and the V-belt is torn, a non-working radiator fan can cause the coolant to overheat, especially when idling for a long time, such as when driving in traffic jams. However, if the fan is not working, it is not necessary to stop driving.
After the engine has cooled down a bit, you can drive it to the nearest workshop at low speed and medium revs. You should monitor the temperature readings and the control lamp
Idling and slow movement in such a situation are harmful to the engine. In this case, the cooling air does not flow around the radiator fins. It is necessary to continue moving at a low speed. It is necessary to try to find the cause of the malfunction and, if necessary, short-circuit the thermal switch.
Troubleshooting
Check the fuse first.
If it is OK, disconnect both wires from the thermal switch or the dual plug.
Connect the contacts together or short-circuit the plug using a piece of wire.
If there is a two-stage thermal switch, all three contacts must be short-circuited.
If the fan now turns on when the ignition is on, then the thermal switch removed from the electrical circuit is faulty.
To proceed further, you should short-circuit the plug with a jumper or a piece of wire.
To prevent loose wires from causing trouble, tape them with adhesive tape or a plaster so that they do not short-circuit.
If short-circuiting the thermal switch does not help, check the fan relay. When the wires leading to the thermal switch are short-circuited, the switching contacts in the relay should click when the ignition is on.
If this is not the case, you can try to short-circuit the relay. To do this, connect contacts 30/14 and 37/17 with a piece of wire and insert the relay.
The radiator fan should also turn on when the ignition is on. If it now turns on, then the relay is faulty.
The jumper wire should only serve as a temporary aid and should be removed after the trip.
If this method does not succeed, check the fan motor.
Disconnect the plug on the fan motor and connect the auxiliary wire from the positive terminal of the battery to the red/black wire contact instead. The brown wire plug must be connected directly to the negative terminal.
If the impeller still does not rotate, the fan motor is faulty and needs to be replaced.
If the fan is working, you need to check the relay, plug and all wires of the thermal switch and electric fan.
You can continue driving with the fan connected directly to the battery if the auxiliary cable is securely fastened.
The second stage of the fan, if present, is connected to the additional fan switch device by a red/blue wire. To test this stage, you need to connect the wires to the contacts of the red/blue wires as well.
Removal the radiator fan
The radiator fan is removed from the radiator together with the rear trim (fan frame).
With the radiator installed, unscrew the two hard-to-reach lower bolts securing the fan frame. Disconnect the wiring harness from the clamps.
If you have a four-cylinder engine, release the hood release cable.
If you have a five-cylinder engine, unscrew the radiator mount on the left (rubber-metal support).
Remove the fan motor with the frame.
To disconnect the engine from the frame, unscrew the three mounting nuts.
[The original source of the article can be found on the website «AudiManual.ru»]