Battery light question

[Bwuerschmidt]

I have an 06’ GX with 152k miles. I was recently traveling for a month during which my friend was driving my car regularly. When I returned I noticed my battery light was on, so I removed the battery and took it to get charged. After picking it up and replacing it the battery light was still on. I then used a battery tester to test my charging system which stated the battery was bad (which makes sense it was 4 years old almost). So I bought a new battery and the light is still on. I tested the voltage with a multimeter and got these readings with the brand new battery:

Battery cold 12.55v

Idle 13.67v

Load: 13.5v

I have read under load I should be pushing 14+v so is my alternator bad despite not registering as bad on the test?

 

[HALB GEHIRN]

Have you tried advance auto parts? They test batteries, starters and alternators and can perform these test on or off your vehicle. This is a free service for all customers.

 

[Bwuerschmidt]

Yes I’ve had it tested twice there getting about a 13.6v alternator reading with their meter. I’ve double checked everything with my own meter, as well as checked for parasitic draw…nothing. The light is still on so I have no idea what could be causing it.

 

[CO_Hunter]

Check the alt fuse under the hood. I think it is 7 amps, why it is that high I have no idea. It sends signal voltage to ecm. I’m not sure if that being blown/open would prevent charging but it will cause the light to come on.

 

[Bwuerschmidt]

Sweet I will give that a try, thanks

 

[Bwuerschmidt]

Went ahead and switched out alternator. Light is still on, but I am operating at normal voltage when checked with a DMM. Checked all fuses in engine, nothing. Does anyone have any idea as to why the light could still be on?

 

[CO_Hunter]

Have you checked to make sure all connections to battery and alternator are tight and corrosion free? In your first post, your resting battery voltage is low as is idle voltage, at least for initial start up.