Hey,
I am going in circles.
There is no pattern or timing, but the battery light goes on and off. Sometimes it stays on for a while.
Battery replaced. alternater replaced.
When the battery light flickers, it plays with the revs and lights etc. However, starts perfectly fine every time.
How do I find out whats going on or are there any suggestions please?.?.?

 

Year of car and engine type, 4 cylinder or V-6?

Has a shop looked at the car?

Who did the repairs?

 

2002, 4 cylinder
Yep all done through a Service station.

 

The battery light being ON means a problem with the cars battery changing system. Typically this means the alternator (alt) has a problem. However this was replaced with assume no change to the battery light flicker issue. Is this correct?

If the other lights flicker and RPM changes with battery light flicker, then these areas are not getting enough power. The engine needs electrical power to operate plus the throttle (RPM) is electrically controlled.

The alt generates electrical power. This power ties into the cars electrical system at the 100 amp ALT fuse.

The alt also needs several other wiring connections to it to work. If these connections are intermediate the alt will stop making power when a connection fails.

If the alt really is OK, the next areas to check are the cars wiring, fuses, battery cables, connections, etc.

Have someone inspect all electrical connections to the alt. The wiring end terminals could be corroded, damaged or the wires frayed. A intermediate problem connection here, can cause the alt to stop making power.

Check the battery cable connections, both at the battery and the battery ground connection to the chassis.

Check the 5 amp ALT-S fuse which sends power to the alt. Plus the 100 amp ALT fuse which the alt output power connects to when tying into the cars electrical system and battery.

WalMart, Harbor Freight, auto parts stores sell a low cost volt meter that plugs into the cigarette lighter. Might pick one up.

When the battery light comes on, determine if the meter voltage suddenly drops. A drop in voltage can cause your symptoms with the other lights, RPM, etc.

When the engine at 2000 RPM, the voltage should be approximately 13.9-15.1 volts. This will change with the number of electrical items being used.

Have you told the gas station about the battery light coming on?

If they replaced the alt and battery. At this point they should be checking the cars electrical system.

The engine being able to start OK, means the alt is generating enough power over time to keep the battery charged.

Engine off and ign key on, the cars voltage at the meter should be around 12.9 volts.

 

Hey Joey,
Yeah no change to the light. It settled down tho, after about a week, but has started again.
Battery voltage check has been down. The reason we thought of getting the alternator tested was because the battery was being over charged. Anyway the altnerator was replaced, battery voltage check done and passed.
I believe the fuses were checked and they seemed ok.
So your suggestion would be to get an auto electrition to check it out properly?

 

If you have volt meter can check the alt voltage yourself at the battery.

Yes, find someone who check the wiring. Assuming the replacement alternator is OK, the issue could be wiring. Note that wiring issues might cause alt failure.