Low voltage, I've replaced everything

Things I have replaced or done:

- New rack and pinion (because power steering went out BEFORE I had battery issues)
- New power steering pump
- Cleaned the battery terminals and cleaned the ground that goes from the battery to the truck
- New Battery (optima red top, new as of last week)
- New 150V Alternator (from toyota, not a reman)
- New Fuse link within the engine compartment
- New serpentine belt
- I've checked all the fuses. My airbag sign is on and my turn signals don't work. I've checked all 7.5 amp fuses, none have popped.
- I disconnected the ground while the truck is running and the battery dies

Things I've checked with a multimeter:
- battery (reads 11.37 volts with the truck running)
- Alternator (reads in the lower 11v range meaning it's not working but it's only 3 days old)

Things that happened yesterday after replacing everything:

- battery died
- Alternator reads low 11v

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All this happened right after I installed a new rack and pinion. I dropped the front diff so it makes me believe I disconnected a ground somewhere but I don't know where. There's only 2 grounds that go from alternator to the battery, right?

What have I missed?

 

Alternator is not putting out power. Check the connections for the regulator, grounds, and possible tripped fused links.

Power should be 13.5+ while running.

 

Is there more than one fuse link other than the one in the engine bay main fuse box?

Where is the voltage regulator located?

 

Double check the routing of the serpentine belt, not routing correctly may cause issues.

 

Make sure the alternator is putting out the correct voltage too..... just because it's new doesn't mean it's working correctly.

 

Yeah that looks good too

 

How would I measure that? Just putting a multimeter to the alternator power and then to a ground?

If so, I did that and it reads in the low 11v range. The old alternator was only on for 1 year. So that means I've burnt through 2 alternators within the last year.

 

Well it seems like you may have a defective new factory alternator

 

Yeah it looks like that might be the problem...

BUT is it possible that a ground that I missed would cause the alternator to read 11v?

 

you can try adding another ground from the engine block to the frame to see if it would change anything

also do you have any dash lights on? Normally if it is an alternator issue the battery light would stay lit on the dash

 

The battery light is not on.

What is on, is the airbag light. I checked the 7.5 amp airbag fuse and it hasn't popped.

Also my turn signals don't work.

 

Look under the dash in the interior fuse box for the 7.5A LH-IG fuse. It looks to be the trigger to enable the IC regulator inside the alternator. It is also responsible for powering your flasher relay. Reasons your blinkers are not working either.

 

I'll take a look and I'll let you know what I find in about 15min

 

Pull it all the way out and make sure the fuse is clean and good. Hopefully it is just blown and replacing it will fix your issue. The fact other systems are not working (blinkers ect.) leads to me think you have a broken circuit somewhere and not just a bad alternator.

 

HOLY SHIT BALLS THAT WORKED!!!!!!

 

It's weird because the fuse didn't pop. I just replaced it with a newer fuse and boom. It worked.

 

The old one definitely looks to have a darker tint up towards the top. The spades are dirty and corroded. It doesn’t appear to have “popped” fully but it definitely wasn’t making a good clean connection.

Awesome news that it’s fixed. I know problems like this can drive people crazy. The turn signals not working also was a big hint at being able to pinpoint this.

I assume you are now getting 13-14v on the battery when running?

 

Yeah I just tested the battery, it's reading 13.8 volts. Thank you so much. If I had your address, I'd send you a visa gift card lol

 

No worries, glad it’s fixed now you can go enjoy your truck. In other news you now have a new battery,alternator, ect that you might not have needed but at least you won’t have to worry about them for several years now.

Did the airbag light go off? I assume maybe not. Airbag codes seem to be harder to clear. A friend or Toyota dealer with Techstream can read them and clear them.

If it’s still on, I would read the code, make note of it and them clear them. See if it comes back. Sometimes the airbag codes stayed stored even when the problem is fixed.

 

Damn you know your stuff haha yeah that airbag light is still on.

Next thing on my list, replace all my fuses so that this won't be a problem for a long time.

 

Just had the same issue on our 2012 Sequoia. Everything from blinkers to butt heat worked but it seemed as if the alt wasn't turning on. Pulled that LH-IG fuse (which did not look blown) and popped in a replacement. Went from 12.5v to a hair under 14v. Engine off voltage went from mid 10s to 11v + (and hopefully climbing as I run the truck more). Thanks much to @Jeff_5_7 for naming that fuse.