Battery light on

Starter replaced about 4 months ago. The mechanic put in a new battery cuz he said that was the problem but it did nothing. He tested the alternator he says it's putting out 14v but I still think it's the problem. The alternator is the original one idk if that makes a difference

HOW he 'tested' the alternator would make a huge, i mean big , like the best , (sorry!) difference. Voltage output alone , is not enough to verify a good alternator. Current or amperage must also be measured with and without 'load' , to more accurately determine a failure. Simple example; I had an Odyssey in about 3 weeks ago, people had to jump start it 2days in a row in the morning, ran fine the test of the day. Their last trip (any night for them) involved driving in the dark , so lights and A/C were on (creating a high 'load' condition) . They jumped it to bring it to the shop, it was parked and sat for about 3hours before I got to it. It started up immediately for me, I brought it in and put my 'voltmeter on it for a quick test- 14.2 volts-seemed okay, but I heard the telltale whine that is characteristic of some alternators when going bad. I continued to let it run and watch the voltage drop steadily for 10 minutes. Slowly went from that 'good' 14.2V down to 11.43V. The 'BATTERY' symbol came on and the display said"check charging system"---so I did-With the REQUIRED (for Honda warranty-Honda dealership).... Tested twice , the tester said "no problem found"....the manager signed off on it and I replaced the faulty alternator.. Problem solved... Moral of the story, common sense and being smarter than what you're working with (plus 30 years of this shit!) goes a long way! Have the alternator TESTED by some experienced , then with information gained from that along with what else you have, decided on the appropriate action. HINT: battery must be fully charged for accurate results!!

Thank you! Everything you said is what was going on with my truck! I might be a female but I know a little bit about cars he's just trying to play me cuz I told him to replace the alternator anyways and he kinda got mad. But he said the alternator tested at 14.5v and slowly went down to 12v so he said it was good but I didn't think so. The battery he put in was enough juice to get me home then car shut off while I was driving it when I tried to jump it it ran for a couple secs and shut off I told him to come get it and replace the alternator and he said that's not the problem.

Just when I thought I was being to 'long-winded'! IF he is insisting it is NOT the alternator, then he should be able to do one of two things; PROVE the alternator is charging properly after 15 minutes under heavy load, or 2: PROVE what IS causing the problem (discharged battery)...I am tempted to suggest a different shop , if you have the choice , and just tell them symptoms and history ,NOT your diagnosis (as we are BOTH assuming at this point) good luck , please post the results!

I told him to change the alternator and he did and problem solved lol he was mad to cuz I was right he was like the battery light went off and the battery stayed charged over night lol I was like really you should find another profession

Glad it's done!