2011 5.7L. New alternator, but Red Battery warning light is on.

My Mech put in three alternators thinking that the problem was the alternators. Last, but in an OEM 150A alternator, but the red warning battery light still wil not go off. Had it diag. at Toyota dealer and found no faults but the light is still on. WTF here. Can someone help out?

 

Try disconnecting the battery for 15min? Let it reset? No codes?

 

Disconnected for an hour. Let it reset. Then plugged in and no codes. Still red.

 

Shot in the dark...could it be grounding issues? look at the grounding wires.. I dont know where they are located in the truck but I am sure others here can guide you on that..

 

Well I had the pinion, power steering pump, serpentine belt and alternator changed. - did the alternator as PM as the old one had 150K on it was was soon to go. I took this to Toyota dealer and they hooked it up to their computer. It showed no fault, no grounding issues and everything was A-OK. Is there an alternator solenoid in the fuse box? I am checking this out. If the battery and or truck was not grounded I am not sure this would effect the battery warning light. It is strange that this light is on and everything has checked out ok at the dealership, they could not explain it. I have checked the grounding wires and I see nothing is disconnected. Thing is this happened after two good alternators where put in it, my old one did not fault it was replaced before any warning light was on. It came on after two new alternators where put in. The battery is getting charge. everything is as it should be, biut there is a fault light.

 

I don’t have a wire diagram for this year but usually the warning light is a separate circuit from the charging circuit. I would guess a fuse or disconnected (broken?) wire on the indicator circuit if it is charging. Maybe a pin in the connector got bent.

Looking at the wire diagram for my 2008 I would check the indicator fuse first. Then check the connector. Then the circuit itself.

 

Link for the lazy for the wiring diagrams. - https://www.tundras.com/threads/ultimate-wiring-diagrams-collection.81448/

Dont know which year is your Tundra or I'd link the exact one.

 

There is a wiredia on this blog. Issue is I cannot find the Charing Warning light in the 450+ pages on the document...

 

Here is the URL to the wirering Dia: https://www.tundras.com/threads/ultimate-wiring-diagrams-collection.81448/

 

Page 130. Same as the 2008.