Alternator troubleshooting, 2018 Tundra 1794 Crew Max 5.7L

Hey guys - I'm new here, and certainly not a mechanic. My question is: Which fuse(s) should I check before looking at replacing my alternator?

My wife was driving to pick up our kid from school and noticed the red battery light on. On the way home from school, the truck stopped and she parked it. I was able to get the battery to Autozone and charged it to full, then put it back in. Autozone tested at the battery with their tool, and said the alternator is bad.

But as I'm researching online, it seems there could also be a bad fuse for the line that allows the ECU to regular the alternator's output to the battery. (Forgive me if I sound dumb, definitely not a mechanic.)

I'm having a very hard time finding out which fuse(s) I should check before I look into replacing the alternator. Help!

 

The one labeled ALT-S 5 Amp. Right above Security Horn on your second pic.

And here's the link to the info:
https://imgvehicle.com/toyota/tundra-ii/fuse-box#section_1

 

Made some correction: Fuse is 5 Amp and not 15 amp.

 

Thanks so much for the reply! I checked the 5 amp fuse and sadly, it looks good. I went ahead and replaced it with the spare anyway. Started the truck up (battery has been charged) and still, showing the red battery indicator in the dash.

Any other suggestions for troubleshooting before we assume the alternator is indeed bad?

Thanks again!

 

If it’s the OEM battery, replace it. It seems once they go bad they are done.

it may read full charge but you may have a dead cell. There are other threads about this issue with t batteries. Good luck

 

Thanks for the recommendation. This isn't the OEM, I already replaced with a brand new battery about 6 months ago. Just meant that I had to charge the new battery when the truck stopped for my wife.