07 SR5 Dead battery after 1 day

[evan1242]

Hey guys so I have a 2007 SR5 that is having a dead battery after one day of sitting. I have narrowed it down to this fuse in the engine bay (see pics)
Do you guys have any idea what this could be? Maybe an alternator? I never seem to get more than 13.5 volts charging even when driving.

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[importman]

Hey guys so I have a 2007 SR5 that is having a dead battery after one day of sitting. I have narrowed it down to this fuse in the engine bay (see pics)
Do you guys have any idea what this could be? Maybe an alternator? I never seem to get more than 13.5 volts charging even when driving.

Imgur: The magic of the Internet

I'm afraid you've got to dig a little deeper. That's a main fuse or what I've always referred to as a fusible link, even though technically it's not. It supplies power to multiple circuits. I found a fuse box diagram and it appears to be fuse #40. This is what it supplies power to: 40 AM1 50 All components in "ACC", "CIG", "IGl", "ECU-IG", "FR WIP-WSH", "RR WIP", "RR-WSH", "4WD", and "STA" fuses.
If you want to look at the diagram it's here: Fuse Box Diagram Toyota 4Runner (N210; 2003-2009)

Hope the link works, and I hope this helps a little. Good luck.

 

[evan1242]

I'm afraid you've got to dig a little deeper. That's a main fuse or what I've always referred to as a fusible link, even though technically it's not. It supplies power to multiple circuits. I found a fuse box diagram and it appears to be fuse #40. This is what it supplies power to: 40 AM1 50 All components in "ACC", "CIG", "IGl", "ECU-IG", "FR WIP-WSH", "RR WIP", "RR-WSH", "4WD", and "STA" fuses.
If you want to look at the diagram it's here: Fuse Box Diagram Toyota 4Runner (N210; 2003-2009)

Hope the link works, and I hope this helps a little. Good luck.

Awesome! Thank you for that link. That will definitely help me narrow it down some more.
I’ll report back with what I find next.

 

[randy88fj62]

My scangauge II shows my voltage while driving as 13.8-14.0 volts. When I turn the truck off it rests at 12.8 volts.

If your battery is dying after one day then you have a power drain or your alternator is dead. What does your battery voltage show at idle with the truck on?

Have you done any electrical mods like adding a dual usb port in your center console?

 

[DblZeta]

It could be a bad battery. Check each cell with a hydrometer. If one cell is lower than the rest that cell is bad. Each cell is worth 2.1 volts. A battery with a bad cell will read 10.5 volts on a voltmeter. Most alternators wont make up the 2 volts while running. The bad cell will drain the battery like a light bulb that wont shut off. A load test on the battery will show a bad cell, the bad cell will boil furiously while on load.

 

[rwh963]

my vote is alternator.

 

[Drcoffee]

I found this thread was a good resource for understanding the cars electrical system.

DIY:CHARGING SYSTEM FULL DIAGNOSTIC(alternator/battery) | Lexus IS Forum