What causes unstable charging current?
2 Answers
Unstable charging current may be caused by a slipping fan belt. Below are the reasons and solutions for unstable charging current: 1. Unstable charging current may be due to poor wiring connection between the battery and the generator armature terminal; dirty slip rings or poor contact between the carbon brush and slip ring, weak carbon brush spring; burned or dirty regulator contacts, etc. When the alternator is operating, the ammeter needle swings back and forth, the charging indicator light flickers, and the headlights dim and brighten intermittently during nighttime driving. This indicates unstable charging current from the generator. 2. Charging system inspection: Check if the generator drive belt tension is appropriate, replace or adjust as needed. Inspect the engine drive belt tensioner and replace if necessary. Examine the wiring connections between the generator and battery terminals. Use a test light to check the generator while the engine runs steadily. If the test light brightness fluctuates, it indicates a generator fault. If necessary, disassemble and inspect the generator, checking the brush contact condition and whether there is poor contact in the rotor and stator coils.
I've also encountered unstable charging current before, which is usually due to a problem with the alternator, especially when the voltage regulator inside is aging or malfunctioning, causing the current to fluctuate. A loose belt can also lead to unstable alternator speed. First, check if the battery terminals are loose or corroded, and try cleaning them with a cloth. If the ammeter on the dashboard fluctuates significantly while the engine is running, don't delay—this can easily burn out the battery or cause the engine to stall midway. Regularly checking the belt tension is crucial; pull on it monthly to see if it's loose. I once neglected this with my old car, and it resulted in a dead battery and unnecessary expenses. If you notice any issues, it's best to consult someone knowledgeable about cars or take it to a repair shop as soon as possible—don't push your luck, as road safety should always come first.
