Battery dash light flickering on and off

My 1998 Toyota Tacoma 3.4L battery dash light has been flickering on and off for about a week now. When the light comes on, my vents blow almost twice as hard if they’re on and the headlights/interior lights shine brighter.

I first went to autozone and got the alternator tested but they said all is good (the battery light never came on while they were testing). I suspected that the alternator was overcharging when that light came on so I hooked up one of those micro mechanic Bluetooth ODB2 scanners to it and drove around until the light came on while monitoring my voltage. When the battery light came on my voltage jumped to ~16.0v.

Does this mean that my alternator is going out?

I also have a couple of screenshots with a graph reading of the voltage that I can post below if they would help.

 

Dont wait too long to replace the alternator... the filaments in the bulbs dont like over voltage.

 

Time for a new alternator. You can buy this one off Amazon and you gain a little amperage over factory and it's a Denso. Only difference is you need to drill the the threads out of the bottom hole.

$165 Denso First Time Fit Alternator - 210-0461

https://www.amazon.com/gp/product/B000EQ94NO/

 

Really the only thing it can be is the alternator. Everything that regulates itself it built in..

If it was a scenario where it was undercharging intermittently then there would be a reason to check battery cables, grounds, etc..

I like a reman Denso unit personally..

 

I agree. I would NOT go with the Duralast from Autozone.
Unless you don't care to spend a lifetime on the warranty. (Yes, you read that right)

Denso for me too.

 

Rebuild the original alternator.

 

Thank y’all for all the replies. I’m currently waiting to get a quote to get mine rebuilt to decide if I’ll be buying a new (to me) denso or going the rebuild route.

 

I bought a rebuild kit for my alternator. The rebuild kit wasn’t expensive. Not too difficult. After assembly i took it to Oreillys and they tested it. Worked out great.

 

For anyone in the future that may find this useful.

it was my alternator. I got it rebuilt buy a guy locally and has been working like a champ. I appreciate the help from everyone that replied.

 

AutoZone sucks! I installed 3 remanufactured ones in my girlfriend's Corolla. All three failed within a day or two.

I finally broke down & bought her a Denso. No problem since.

 

Denso definitely seems to be the way to go according to this forum and YouTube and I can’t say I have an argument against it myself.

 

Not a fan of Autozone anything....stuff just never seems to last.

 

Hopefully that won’t be the case for a brake booster I got from them a few weeks ago. At least it’s easy to get to and take out should I ever need to cash in on that lifetime warranty.