Battery Light (1 Viewer)

[Cj80cruiser]

A couple nights ago my wife and I were headed to the grocery store....about a 16 mile round trip. The battery light came on shortly after leaving the house but the GX rode fine for the duration of the food run.

My wife took the car to work today at around 12 miles round trip. She did make time for a quick trip to autozone on her lunch break to get the battery tested. The guy there told her the battery was down to 26% of its full charge.

She was just barely able to make it home today with the car pretty much dying in the driveway. She turned the air off and radio about a mile away from home just to have a chance of making it home. After she parked it, that was it, the GX won't start now.

I'm leaning towards this being the alternator since it was such a gradual decline of power and it's never had any problem starting. What say you? Could this still be the battery? Battery is about 2-3 years old and looks to be bought at the Lexus dealership by the previous owner. This is a 06 with 75k miles.

I found a few replacement alternators
1) OEM $342
2) Mean Green $399 http://shop.mean-green.com/2007-03-4-RUNNER-47L-MG13983.htm
3) DC Power $389.95 https://www.dcpowerinc.com/fit/Toyota~4Runner~2007~4.7L-V8-2UZ-FE/13994-180-hp.html#tab-vehicle_fits

 

[BlackUSK56]

Cory, if the vehicle showed any sings of hesitation or miss firing while driving, I would say its the alternator. You can start a car and then remove the battery, and it will still run because its being powered by the alternator while the engine is running. If the alternator craps out then engine will pull all the power it requires from the battery until it is low, and that's when you notice it acting up.

My best friend, who is a Cadillac Dealer engine and transmission mechanic, has referred me to www.rockauto.com for generic OE style replacement parts. They have a remanufactured Denso alternator for $117.79 and a $72 core charge. http://www.rockauto.com/catalog/moreinfo.php?pk=1292607&cc=1431005&jnid=372&jpid=4 Looks like a good fit.

We had a battery with dead cells on my wife's Camry. The battery would show 12.8 volts, but barely have enough amps to turn the engine over. After jumping it, it would run flawlessly, because it was being powered by the alternator while the engine was running. I took it to Toyota, they said the battery was low, charged it for about 20 minutes, connected it to their tester, and it failed in less than 5 minutes. This was the original battery in a two year old car, we bought new.

Basically:
Problems while engine running = alternator
Problems only at start up = battery

 

[Godwin]

If it is the alternator I recommend you talk to Edd at Auburn Starter and Generator in Auburn. They're located on College Street at the RR crossing. I've had several alternators rebuilt here over the years and they've always done a good job and a lot cheaper than if buying a new or remanned unit.

 

[ChiTown]

It's the alternator, the car was running on battery only hence the state of depleted charge. Put the battery on a slow charger to get it back to the proper level and replace the alternator, you'll be fine after that.

 

[rustydrummer]

I'd say the alternator as well. Had the same symptoms on my wife's GX, '06 at 105k miles a couple months back. Changed it myself in the garage. It is a bit difficult to get to. I had to go through the passenger side wheel well. You'll have to loosen the power steering pump and maybe a few other things and There's only one way it will fit in and out. Bit of a PITA, but do-able. Back to running great again. Good luck. Ryan

 

[Cj80cruiser]

Thanks for the replies. My dads jump box had an alternator tester on it and it read the alternator as good. I'm borrowing a tester from a guy at work just to get another test before I get a new battery. My weekends are really long so diagnosis is going to be slow until mid week.

Godwin, I will talk to Ed if this does turn out to be the alternator. I have my fingers crossed that this is somehow the battery but the symptoms have me leaning toward the alternator as many on here have diagnosed as the problem.

 

[GXO]

Alternator. Mean Green is awesome since you get more amps for the dollar. Rewinding it to more Amps locally is the other option (often cheaper).

 

[ChiTown]

Easiest way to test an alternator is with a simple volt meter. Start the car and put the volt meter on the battery, you sound see 14v+. If you see anything less that 13.5v it's not charging correctly. If you see 14v+ turn on every accessory in the car (a/c, rear defroster, seat heaters, radio, high beams, everything you have) see if the voltage drops below 13.5v. If it does the alternator is not charging properly. If it doesn't than it may be ok. Do these tests cold and hot.

 

[Mlachica]

it's your alternator...apparently it's sorta common among the gx's.

 

[GXO]

Mine is at about 80% capacity so I will be replacing soon. Very common with any car as it ages, and all the GX470s are aging now

 

[The Great Him]

check the connection at the fuse block/box under the hood. i had this very same issue a couple weeks ago, turns out that the nut holding the main power wire into the fuse block had worked lose and eventually shorted out, created enough heat to start melting the plastic block, and burned the copper contact on the end of the wire... anyhow after read up on the forums and spending $300 on a new alt and 3 hrs of labor i had the new one swapped in and started the truck up to still have the light on and only 12.x v. i was pissed and started looking at the fuse block for a blown alt fuse. thats when i noticed the melted area around the wire. anyhow pulled the nut off, cleaned it up good on my bench grinders wire wheel and wire brushed the copper contact and put it all back together and boom 14.x v. so i turned in an old junk 22re alt as my core and kept my good gx denso alt as a spare. but getting a higher output alt is not a bad idea, as these rigs are very taxing on the stock alt, not a lot of room to spare especially if you ever plan on adding a winch or lights etc. it could be a alt and if it is, there is an easier way to get it out than what the book says or service manuals tell you to do.

-pull it out through the bottom and the side. pull the front passenger tire, and the front most inner fender spash guard(the one in front of the strut tower). then undo the serpentine belt and unbolt the PS pump(i removed the pump via the bracket ie left the pump attached to the bracket) and set that off to the side, then unhook the alt and pull it our through the opening you created in the wheel well. installation is reverse order half as much time. good luck. let me know if you have any other questions. i have pics of the process too

 

[Cj80cruiser]

check the connection at the fuse block/box under the hood. i had this very same issue a couple weeks ago, turns out that the nut holding the main power wire into the fuse block had worked lose and eventually shorted out, created enough heat to start melting the plastic block, and burned the copper contact on the end of the wire... anyhow after read up on the forums and spending $300 on a new alt and 3 hrs of labor i had the new one swapped in and started the truck up to still have the light on and only 12.x v. i was pissed and started looking at the fuse block for a blown alt fuse. thats when i noticed the melted area around the wire. anyhow pulled the nut off, cleaned it up good on my bench grinders wire wheel and wire brushed the copper contact and put it all back together and boom 14.x v. so i turned in an old junk 22re alt as my core and kept my good gx denso alt as a spare. but getting a higher output alt is not a bad idea, as these rigs are very taxing on the stock alt, not a lot of room to spare especially if you ever plan on adding a winch or lights etc. it could be a alt and if it is, there is an easier way to get it out than what the book says or service manuals tell you to do.

-pull it out through the bottom and the side. pull the front passenger tire, and the front most inner fender spash guard(the one in front of the strut tower). then undo the serpentine belt and unbolt the PS pump(i removed the pump via the bracket ie left the pump attached to the bracket) and set that off to the side, then unhook the alt and pull it our through the opening you created in the wheel well. installation is reverse order half as much time. good luck. let me know if you have any other questions. i have pics of the process too

Thanks for this. I haven't checked the fuse box yet so I'll give that a look this afternoon when my wife gets home from work. I bought a CTEK battery charger and plan on charging the battery everyday until I can get the time and money together to buy a new alternator....probably going with mean green since there is a wait for the DC power alternator.

My co-worker forgot to bring the alt tester so that option fell through. I charged the battery up and it tested good at Autozone. I cleaned the terminals really well and connected everything back up...surprise, surprise, battery light was still on. Alternator will be swapped out in the near future.

I'll have to call Mean Green's customer support to see why they have different alternator model numbers for the same 4.7L motor used in the 4runner, Landcruiser, and Tundra.

 

[The Great Him]

They probably have different alts because there was two different alts from Toyota. One was a 100amp unit stock and the other was a 130amp unit. I believe the Land Cruiser(100series to include the lx) and GXs got the 130, while 4runners Tundras and Sequoias got the 100amp alts. They all physically are the same and have the same hookups. So it should not matter.

 

[Cj80cruiser]

If it is the alternator I recommend you talk to Edd at Auburn Starter and Generator in Auburn. They're located on College Street at the RR crossing. I've had several alternators rebuilt here over the years and they've always done a good job and a lot cheaper than if buying a new or remanned unit.

Planned to go with Mean Green but after talking to the owner at Auburn Generator and Starter I was convinced he could produce a satisfactory upgrade to the stock alternator. Also, like you said, the price was another bonus.

 

[Cubiclegangsta]

Hey folks. I have a series 100 (2000). The battery light is on but it’s running fine. Bought a battery a week ago. Additionally my mechanic said that the click that happens when it won’t start (occasionally) is the starter. Do you think I need a starter and alternator or is this a deeper underlying issue

 

[CarolinaGX]

I would trust your mechanic. The alternator runs the truck and charges the battery and would be the culprit for the battery light. I would replace the starter as it sounds like it is getting ready to leave you on the side of the road.

 

[sexilexi470]

Having the same problem on my 04 Lx . Battery light came on. Put my volt meter ony battery and revved my engine up to about 2500-3000rpm to see if the voltage would go up but it stayed the same. . Tested the battery, checked out to be good but low charge . So i tested the charging system and checked out for "no output" . Inspected and checked the fuses and it looks good . 99% alternator gave out . . .