Battery indicator light on

The detailed test results are above in my original post.

TLDR:
The voltage reading while the engine was running was 13.87V with the accessories on. This was after the battery indicator light turned off a couple of days later.

Before, when the battery light was on, the voltage reading with the engine running was 13.7v. This was without any accessories on. Also, there was a loud whining sound

 

Yeah, definitely stay away from AutoZone. I had to replace my girlfriend's Corolla alternator three times because of their junk. One of them also ruined the battery.
Check the battery when the light is on, should be around 14V or so. 12.6V with the truck off is where you want to be. Good luck

 

Really need the whining sound and/or the warning light to come back. That will be the best time to get useful test results

Or just throw an alternator at it

 

There’s more to it than voltage.
But I think the regulator monitors voltage for the charge light circuit.
Current can’t flow without voltage.

Toyota wants you to disconnect the charge wire.
Then test voltage and amperage.

13.2- 14.8v @ 2,000 rpm

10A or less @ 2,000 rpm - No Load
30A or more @ 2,000 rpm - w/Load (Headlights on High, and Blower to Hi)

 

I agree.
I would feel comfortable throwing one on it.

 

Agreed, I'm just going to replace it with an OEM one at this point. At 180,000 miles, I feel that the original one has done its job well.

Also, that alternator whine was loud and unmistakable. So, it's most likely on its way out.
Plus, who knows when the battery indicator light will come on again.

 

It will come on right before it leaves you stranded on the road side.

 

HAHAHAHA exactly... one of the many unwritten rules of driving lol

This is the reason why I haven't driven it yet. Plus the rainstorm that is happening right now.

 

@guyofnowords what was the solution?

 

Know it’s an old thread but it’s sounds like my problem plus some. When the battery light first came on the dash I got some supplies together and then noticed my dome light dimming and getting very bright. Then my radio would cut out. And cherry on top both my headlight bulbs and one parking light bulb blew. Both high and low beams.

At this point I went to AutoZone to get battery alternator and starting system checked. Of course battery light was off and they said my starting system was bad?

I know it was a fluke but at home with voltmeter with engine running it first read 15-17 volts jumping between those and then the battery light went out and then it read 14 volts like normal. Battery was normal voltage at rest.

Decided to take alternator out and check continuity and resistance of diodes, slip rings, and b terminal. They seemed fine and checked brushes not really sure what bad brushes look like so I’ll put a picture below.

The voltage regulator would jump between 0-3 ohms of resistance and then to 1000-1500 ohms. Not sure if that’s a fluke but I’m guessing voltage regulator is out (guessing my bulbs got a huge surge and blew) and as far as I know that part can’t be replaced and an all new or reman alternator is needed. Any agreement, disagreement, or suggestions are appreciated.

 

I have this problem now with the battery light on. Tried 3 alternators, 2 new and one from a buddy’s truck that’s perfectly fine and the battery light still on. 3 different batteries, 1 bran new and all voltage checked and good. I cleaned all the grounds and even added 2 new ones from the frame to the engine and engine to firewall, cleaned all the connections, battery cables and terminals. Voltage showing anywhere from 13.8 to 13.99 at idle and 14.05 at 2000RPM at the battery. Just wondering if anyone has had or seen this problem before and what was the fix.

 

Check your ALT-S Fuse (7.5A) in the engine room fuse box.

https://www.tacomaworld.com/threads/2nd-gen-information-diagnostics.784008/#post-28042155

 

Turned out to be the white wire to the fuse box. I changed the white wire a few days ago but the little piece of it that I never turned out to be the problem. Appreciate the help

 

2002 TRD 3.4, alternator died last night; 336K on it, original