Each engine is turned on during operation by a switch, which is controlled mainly by hand. In the case of an antenna with an electric motor, the switch is controlled automatically by the radio receiver.
Check the fuse for the corresponding electric motor and replace it if necessary.
Note: For electric windows and central locking, the cause of the overload must be eliminated before switching on again. This could be, for example, ice on the windows and locks or dirt on the door window guides.
If the fuse blows immediately, then a short circuit is assumed.
To accurately determine whether the engine is working properly, connect two auxiliary wires (diameter 2 mm) to the engine directly from the battery, observing the polarity of the connection. In doubtful cases, the positive (positive) contact can be determined from the electrical equipment diagrams. To do this, you need to remove the electric motor, if necessary. All electric motors in the car are powered by the battery voltage (from 12 to 14 V). If the engine now operates normally, then the voltage supply circuit is faulty.
Note: If the engine runs very slowly or stops, this indicates worn brushes. In these cases, the brushes must be replaced.
If the engine is running, then the electrical diagram must be used to determine which wire supplies voltage to the engine when the switch is closed and the ignition is on (not in all cases).
Check the voltage supply wire to the motor with a test lamp. Since electric motors consume a lot of current, you can use a regular incandescent lamp with two wires for testing. This is the easiest way to check the voltage supply. Motors that can rotate left/right, such as electric window motors, have two positive contacts.
Note: Checking the windscreen wiper motor is described in the relevant chapter.
If there is no voltage supplied to the motor, the voltage supply circuit is faulty. The fault in this circuit should be looked for using the electrical equipment diagrams. Electric motors are usually connected using additional relays due to the high current consumption. Relay testing is described in one of the following sections.
If there are no faults in the circuit, check the switch.
If the wire is faulty, it is often easier to lay a new wire, since it is quite difficult to determine the location of the damage in the wire.