Generator operation (diagnostics)
These vehicles are equipped with internally ventilated alternators with a built-in voltage regulator and a warning light on the instrument panel that operates as follows:
- when the card is installed in the reader in the 1st fixed position, the signal lamp lights up;
- when the engine is started, the signal lamp goes out;
- If the warning light comes on again with the engine running, this indicates a circuit fault in the charging circuit.
Troubleshooting
The signal lamp does not light up when the card is inserted into the reader in the 1st fixed position.
Check the condition of the electrical connections, lamp serviceability (to do this, close the circuit on «mass»; the lamp should light up).
The signal lamp lights up when the engine is running.
This indicates a malfunction in the charging circuit, which may be caused by:
- broken alternator drive belt. broken wire in the charging circuit:
- internal generator fault (rotor, stator, valves or brushes);
- voltage regulator malfunction;
- excess voltage.
If there is a battery charging problem and the warning light is working properly
If the regulated voltage is below 13.5V, check the alternator. The cause of the malfunction may be:
- a failed valve or diode;
- break in the circuit of one of the phases of the stator winding of the generator;
- wear of brushes or slip rings.
Voltage test
Connect a voltmeter to the battery terminals and read the voltage.
Start the engine and increase the speed until the voltmeter needle stabilizes at the regulated voltage.
This voltage should be in the range of 13.5-14.8 V.
Turn on the maximum number of electricity consumers, the regulated voltage should remain within 13.5-14.8 V.
Attention! When working with arc welding on a car, be sure to disconnect the battery and voltage regulator.
Identification
Data for verification
Note. After 15 minutes of warming up at a voltage of 13.5 V at the terminals.
Diagnostics
Diagnostic tools allow you to check the generator by measuring the output voltage and current with electrical consumers on or off.
Note. Diagnostic Clamp Meter - Inductive Type (measurement range: 0 to 1000 A). Their installation is carried out without disconnecting the battery, which allows you to save the memory and settings of the computer.
Install the clamp meters directly at the generator outlet, the arrow of the clamps should point to the generator (scan tool detects incorrect installation).
The measurement is carried out in three stages:
- measurement of the battery voltage when the card is installed in the reader in the 2nd fixed position;
- measurement without electricity consumers of regulated voltage and output current;
- measurement with the maximum number of electricity consumers of regulated voltage and output current.
At the end of the test, the obtained values are used for diagnostic conclusions: the battery voltage is less than 12.3 V - the battery is discharged.
Without electricity consumers:
- regulated voltage is greater than 14.8 V - the voltage regulator is faulty;
- (regulated no-load voltage less than 13.2V) or (charging current less than 2A) charging circuit failure.
With consumers of electricity:
- regulated voltage is greater than 14.8 V - the voltage regulator is faulty,
- regulated voltage is less than 12.7 V - it is necessary to check the return of the generator in relation to its characteristics.
If the value of the recoil current obtained during the measurement is small, check:
- generator wear (brushes...);
- battery connections;
- «mass» engine tire;
- compliance of the generator with technical conditions;
- drive belt tension.
If the return current value is normal, with a reduced value of the regulated voltage, the cause is not in the generator.
The following reasons are possible:
- too many electricity consumers are installed on the car;
- the battery is discharged.