battery light

I've unbolted and cleaned around several ground leads to the frame and one to the transmission. Tightened the positve lead at the alternator. Even ran one side of my jumper cables from the negative battery post to the frame and the light is still coming on.
I'm just going to replace the alternator and then just see what happens

 

Well, a new alternator didn't fix the problem...
So I guess like everyone has "said", it must be in the wiring..

 

Well, the new alternator lasted about 10 minutes. Hummed with electrical smell and then zero charge.
Took it off and put the older alternator back on.

 

That's scary ! Please post when U get to the bottom of it.

 

The old/2nd alternator is charging around 13.4 volts.
Ran by Harbor Freight and bought their cigarette lighter tester thingy.
The yellow and green illuminate as they should, but when the battery light comes on the green light starts to flicker.
Atleast I get to keep an eye on the charging status of the battery.
I ran a single 12 gauge CCA wire from the body ground next the battery, to a frame ground and that hasn't help any.
I guess my only other option is to go to the local Toyota dealership and get a new and hopefully not a rebuilt alternator.
At Advance Auto, when looking up the alternators, the question is asked does it have the tow package. Which I just assume it does, since it has the tow hitch and the 4 point socket.

 

If you have these 2 things, you have the factory tow package.

 

Thanks Muddinfun!
Then I dont have the towing package!
Now I've got to do some research (Google it) and find out what the differences are between an alternator with and with out the towing package.
I'm sure what ever the outcome is, it will be cause of something stupid on my part.

 

Well, ran by the local Toyota dealership. The remanufactured Toyota alternator cost $371 and since I didn't have the original Toyota alternator I can't get the $70 core charge credit.
Before I completed my question, the guy at the parts desk asked something like "was this due to my battery light being illuminated?" and I said "yea".
He assured me it wasn't a wiring issue, that it is the alternator.

 

I'm "knocking on wood" and hopefully not jinxing myself for posting this.....
But it's been over a week now since I installed the alternator from my local Toyota dealership and the battery light has not illuminated any.
I was even sceptical on my snapchat posts.
I now can start and finish an alternator replacement including the skid plate and battery removal/replacement in just under an hour

 

Did the new alternator solve your problem?

 

Getting an intermittent and sometimes persistent battery light. Rebuilt this two years ago and carrying a spare.

I checked contacts and lug, but it tests 12.8v cold and 13.9v running. It's an AGM battery, so expect slightly lower voltage.
Has to be something else in the system.

I'll swap the alternator later, but I don't get it

 

I have a 4 cyl, manual transmission, 2006 Tacoma with 273,000 miles on it.

the other night the battery light came on after engine start and stayed on until I reached 50 mph about 10 minutes later.

I took it to the dealer and they tested the battery(failed) and tested the alternator (passed). they sold me a new battery. The one I had was about 6 years old.

the vehicle sat for a day and when I started it I, once again, had a battery light. I drove around town for 30 minutes at 25 mph and the light stayed on. I called the dealer and they said drive it up. The second I hit 50 or so mph the light went out. Does alternator speed have anything to do with this? That’s two data points.

drove it around town today, no battery light.‍♂️

tomorrow I’m having the alternator replaced. After reading this thread it sounds like it’s either the battery or the alternator—and the battery is now new.

 

Yes, engine speed does affect the charge rate.
What you need to do is know the voltage of the battery when you turn the truck off at night.
Then check the voltage in the morning. You may have a draw on the battery.

If you have the alternator replaced, ask them to inspect the wires on the plug.
There have been cases where the wiring corrodes and causes charging issues.

 

Thanks, I’ll do that.

 

Day 2 with the new alternator, about 4 hours of driving and no battery light. I noticed that the tech at the dealer noted the alternator bearings were bad. I’m not sure how they would pick that up on their “alternator test” unless they listened for it or maybe took the belt off and spun the pulley ‍♂️