Battery light on?

CHRISTINA DRESSELL

MEMBER
2014 HONDA ODYSSEY
3.5L
V6
2WD
AUTOMATIC
164,000 MILES

Last week the alternator went bad. Monday it was replaced and ended up needing a new battery as well. Got it all put on and by Tuesday it was running fine. Drove it back and forth to work about 25 miles then the following day drove it round trip about 100 miles. 5 miles from home on our way back the battery light came back on. We tested the alternator again and that is fine and battery connections are good. The belt did have some noise while running though but the serpentine belt itself is fine (not cracking or torn).

Thursday, May 25th, 2023 AT 5:59 AM

3 Replies

KEN L

MASTER CERTIFIED MECHANIC
54,137 POSTS

I would say you got a defective alternator but to be sure, this guide can help:

https://www.2carpros.com/articles/how-to-check-a-car-alternator

And if the system is charging you may need to reset the battery monitor which you can do so by following this guide and video:

https://www.2carpros.com/articles/step-by-step-guide-how-to-reset-an-automotive-battery-monitor

and

https://youtu.be/ETNv2S_idIU

Here is the correct way to replace the alternator. Check out the images (below). Let us know what happens and please upload pictures or videos of the problem so we can see what's going on.

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Thursday, May 25th, 2023 AT 2:18 PM

CHRISTINA DRESSELL

MEMBER
2 POSTS

The alternator was already checked again today and the battery and it all is running at the right voltage but the battery light is still on.

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Thursday, May 25th, 2023 AT 4:54 PM

AL514

MECHANIC
5,499 POSTS

Hello there, looks like there is a battery current sensor on the negative battery post. This sensor transmits battery voltage, current flow, and battery temperature on a Lin Bus network to the engine computer which is what controls the charging circuits. The battery sensor cannot be over tightened, or the circuit board inside can crack. The system needs to be checked using a scan tool capable of reading the live data and see if there are any issues with the battery sensor. The torque spec for the negative battery post is only 2-4.4 lb ft. It is not much. Charging systems have changed dramatically on modern vehicles. The live data for the engine computer (ECM) needs to be checked, also scanned for any possible diagnostic trouble codes. You probably want to bring it back to whoever did the work. Just having the Alternator voltage checked is not enough.

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