Fault Diagnosis And Elimination OF Unsteady Charging Current OF Automobile Alternator

[Generator charging current unstable fault phenomenon](1) When the engine is running above idle speed, the ammeter pointer has been swinging. (2) When the engine is running above idle speed, the charging indicator flashes. (3) When the car is driving at night, the headlights flash. [Reasons for generator charging current instability](1...

[Generator charging current unstable fault phenomenon]

 (1) When the engine is running above idle speed, the ammeter pointer has been swinging. 

(2) When the engine is running above idle speed, the charging indicator flashes. 

(3) When the car is driving at night, the headlights flash. [Reasons for generator charging current instability] 

(1) External reasons: the transmission belt is too loose; Poor wire contact; 

(2) Internal reasons: brush wear stator winding and rectifier contact is poor; Or partial short circuit or short circuit of rotor and stator; The regulator is damaged; [Fault diagnosis and elimination of generator charging current instability] 

(1) Start the engine, switch the multimeter to DC 20V voltage, connect the red probe to the positive electrode of the battery, connect the black probe to the negative electrode. Observe the multimeter and change the engine speed to medium or high speed. At different speeds, the normal voltage should be about 13.8V, if the multimeter value has been jumping, the generator charging current is unstable. 

(2) Troubleshooting. 

(3) First eliminate the reasons for loose belts and poor wire contact.

 (4) If the fault still exists, the generator must be removed: (5) Check the length of the brush, which should not be less than 7 mm. (6) Check whether the connection between the stator winding and the rectifier is loose. (7) Check the rotor and stator with a multimeter. (8) If the above checks are normal, the fault is the voltage regulator. Verify the effect and repeat the third task.