An increase in temperature can cause the coolant to boil off. This can be caused by a non-working fan. The electric fan control circuit can be both relay and relayless.
It is necessary
- - flat screwdriver;
- - side cutters or pliers;
- - wire with a cross section of at least 0.75 sq. mm in insulation;
- - insulating tape;
Instructions
Step 1
Take the electrical diagram of your car and find the elements responsible for controlling the electric fan. First of all, check the integrity of the electrical fuse. Please note that an electric fan was not used on older cars; instead, an impeller was installed on the pump, which rotated constantly. Such a blowing of the radiator is good because the cooling is better in hot weather. But in cold weather, the engine takes longer to reach operating temperature, so you have to cover the radiator with cardboard or a piece of plastic in winter.
Step 2
Check the performance of the temperature sensor installed in the radiator housing. The electric fan may not turn on due to the failure of the sensor, which is a simple switch, the contacts of which close at a certain temperature. With a little reflection, we can come to the conclusion that by closing the contacts of this sensor, we will achieve the forced activation of the electric fan. Taking a look at the simplest control circuit that is used on VAZ cars, you can see that the sensor is installed in the break of the main power wire of the fan.
Step 3
Check the operation of the electromagnetic relay if the fan switching circuit is relay. This can be done by closing the relay contacts connected to the sensor. A faint click should be heard, indicating that the coil is intact. But do not forget that voltage should appear on the positive terminal of the fan. If it is not there, then it is quite possible that there is a destruction of the relay contacts. Opening and closing creates a small spark that can melt even the contacts. Therefore, after checking the coil, be sure to short-circuit the power wires. Just do not short the positive wire to ground.
Step 4
Take a wire with a cross section of at least 0.75 square meters. mm to connect an electric fan to the battery terminals. This decision will be correct if the breakdown cannot be quickly diagnosed. As a rule, a complication of diagnosis occurs when the electrical wiring is disturbed. For example, on cars of the eighth family, the temperature sensor is not connected to the ground at the nearest point, but the wire is pulled under the radiator and goes to the fuse box. In order not to boil in the plug, the best way out is to open the plug connection and connect the fan to the battery. Just do not mix up the polarity, otherwise the motor will rotate in the opposite direction, the radiator will not cool down as a result.
