99 legacy wagon with 2.2 L, IDLE IS QUITE LOW, INTERIOR AND EXTERIOR LIGHTS FLICKER WHEN IDLING (no flicker when engine is off) ENGINE ALMOST STALLS OCCASIONALLY WHEN COME TO FAST STOP.

 

Had Autozone check alternator while car running and no problem indicated. Then they checked the battery and said it was bad so replaced it for free (under warranty). Flickering and low idle are exactly the same with the new battery.

 

Any thoughts?

Edited November 27, 201015 yr by raybo

My guesses are it's still one of those 3. ALternator (most likley), battery (you just replaced) or connections. I'd assume the connections were cleaned when the new batttery went in? If you let them do it that's not a safe bet however.

 

Check the alternator connections at the alt.

 

Often another symptom is the ABS and onother dash cluster light coming on but NOT the alternator light.

I put the new battery in and connections are clean. How can I prove the alternator is bad when they say it checks out? Its under warranty by autozone.

 

Could it just be that the low idle caused by something else is causing the flickering??

also noticed loud static on am radio when engine on.

i have always heard that was a grounding issue.

A possible cause of radio interference and flickering lights is worn brushes and/or slip rings in the alternator. Sometimes you can verify that by tapping on the alternator while listening to the radio, and seeing if the interference changes in level.

Bad diodes in the alternator can also cause the troubles you say you are having. Have a load test done on the charging system to see if it can produce the full rated output. If it falls significantly short of spec then replace the alternator.