Alternator and Battery issue

I have had a charging problem forever with my 2.7 Tacoma. Its a 2009 and when running the battery indicator light comes on. If i rev the motor it sometimes flickers or goes off only to return. It has affected the blower speed of my heater to where the fan doesnt blow air at all. Ive changed alternators 3 times and have been through several batteries can someone help. Also my windshield wiper speed is affected

 

What condition is your serpentine belt, pulleys, and tensioner in?

 

What voltage does the battery show with a meter when running at an idle?

Can you read this? It is the charging circuit for your battery.

 

You can see above that power is applied to the Charge LED in the meter on the anode side of the LED.

If the regulator in the Alternator see's less than optimal power to the Battery it will allow current to flow through the LED which the illuminates.

Since you have replaced the alternator and regulator ( which is part of the alternator ) several times you need to look at the wiring between the Alternator and the other circuits. Particularly the white sensing wire. Clean the connections and make sure the wires are not damaged or shorting to ground.

 

Okay, I hate it when people say this but, now I'm going to...

"This happened to me once in a different vehicle..."
I had a Chevy Luv pickup (don't hate me), that would do this. The light going on was very RPM-dependant. I had a broken wire/intermittent connection in the wires at the plug on the back of the alternator.

 

It’s happened to other guys with a Tacoma.
And it was the wiring at the alternator plug.
The wire actually “corroded” inside the sheathing. Not just at the plug connection.

I remember muddinfun’ mentioning it before.
Here is the post. https://www.tacomaworld.com/threads/battery-light.144814/#post-18685899

You might do a resistance check of the 7.5A Alt-s wire.
Or would a resistance check show anything? @Jimmyh ?

 

I would venture to say if it is effecting the Charge LED it would show up with a resistance check.

 

I didnt get around to the truck yet because we keep getting pounded with snow. Since I posted the truck is stuck in 4 low and constantly pops fuses under the dash and all the turn signal bulbs blew out

 

Well that is no good. What fuses are blowing?

 

Only the 4x4 30amp fuse under the dash

 

As far as I can tell that should be a 20 ampere fuse and not a 30 ampere.

20A 4WD
Multi Mode 4WD and Rear Differential Lock and Rear Differential Lock (2WD).

Maybe water ( Melted Snow ) crept into the 4x4 actuator or the diff lock actuator. Or the indicator switches for those functions or their wiring connectors.

Point being that 4WD 20 ampere fuse supplies power to the 4WD Control ECU which supplies power to the various actuators, switches and motors associated with the transfer case and differential lock (if applicable).