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?

 

That looks like an alternator issue to me...... My alternator gave up the ghost around 150K miles.

 

Ah makes sense, would a parasitic drain cause this at all? Should I go in with a multimeter and test my fuses as well?

 

Well, I would check out all the possible cheaper causes before changing the alternator

 

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?

 

What's normal voltage?
Voltage and charging are two very different things.

Do you have a DC amp clamp? If so check and see what the amps are on the batt when vehicle is running.