battery light on and off

[yariseggvvti]

I got my alternator replace and the battery light on and off. Battery with 100% good. The vehicle running find but the light is on and off. when the light is on kinda blinking dim. Any idea??? Thanks!!

2007 hatch with 72k now. What else I need to check. Ground cable is good.
Autozone alternator is good enough I think. I am going to order one from Toyota. I am going to install it this weekend. Hopefully the solve the problem.

[CTScott]

I got my alternator replace and the battery light on and off. Battery with 100% good. The vehicle running find but the light is on and off. when the light is on kinda blinking dim. Any idea??? Thanks!!

2007 hatch with 72k now. What else I need to check. Ground cable is good.
Autozone alternator is good enough I think. I am going to order one from Toyota. I am going to install it this weekend. Hopefully the solve the problem.

That seems to be a common problem with aftermarket alternators. They don't seem to properly output the signal to the cluster. Have you measured the voltage with the engine running to see what the actual output of the alternator is?

[Geoff Peace]

I got my alternator replace and the battery light on and off. Battery with 100% good. The vehicle running find but the light is on and off. when the light is on kinda blinking dim. Any idea??? Thanks!!

2007 hatch with 72k now. What else I need to check. Ground cable is good.
Autozone alternator is good enough I think. I am going to order one from Toyota. I am going to install it this weekend. Hopefully the solve the problem.

This happens here in the UK with some aftermarket alternators not only on Toyota but other makes as well. If bought from a reputable supplier, usually OK but there seem to be a lot of cheap rebuilds which are not OK. I think the quality of the components used is not up to the mark, particularly the rectifier and regulator. Just one leaking diode will create the problem you describe.

Regards Geoff Peace.

[yariseggvvti]

Thanks for you time CTScott and Geoff Peace.

your information helps a bit. I am going to replace OEM Toyota alternator. I hate the light come on the off. It makes me feel annoying. Lucky I purchase the alternator with 28% off the list price. Dont trust any none OEM replacing parts.

[yariseggvvti]

Finally got the factory alternator in now. Running fine and no more battery light on and off. Spend little extra money taking care the problem is worth.

[CTScott]

Finally got the factory alternator in now. Running fine and no more battery light on and off. Spend little extra money taking care the problem is worth.

What did you do with the bad one? I'd like to take a look at one of the aftermarket ones to see why the heck they all act this way.

[bronsin]

Next time go to the on line junkyard and get an OEM part.with 30k miles on it.

The alternator, water pump, calipers, master cylinder, exhaust system and in fact everything but the MAF and brake pads/shoes on my sons 2000 ECHO with ~180,000 k miles on it are origional.

[yariseggvvti]

I return it back to Autozone. I am using it for about two weeks.

[Ecoman44]

Reviving an old post because I have a similar issue. I have an aftermarket alternator, but it's been in the car (2007 Hatchback) for over a year now with no issues until now. Occasionally, the battery light and airbag light will flash on then off (sometimes just the battery light). When it happens, I can hear a difference in the load on the engine (slight, but it's there). When running, volt meter on the battery reads 14.5v +/- and when not running it reads 13.3v +/-. Could this be the same corrosion issue with the regulator?

[Sir A.Y. Atoyot]

Reviving an old post because I have a similar issue. I have an aftermarket alternator, but it's been in the car (2007 Hatchback) for over a year now with no issues until now. Occasionally, the battery light and airbag light will flash on then off (sometimes just the battery light). When it happens, I can hear a difference in the load on the engine (slight, but it's there). When running, volt meter on the battery reads 14.5v +/- and when not running it reads 13.3v +/-. Could this be the same corrosion issue with the regulator?

Could be intermittently sticking brushes - easy enough to check if you're up for dismantling the alternator.

[CTScott]

Reviving an old post because I have a similar issue. I have an aftermarket alternator, but it's been in the car (2007 Hatchback) for over a year now with no issues until now. Occasionally, the battery light and airbag light will flash on then off (sometimes just the battery light). When it happens, I can hear a difference in the load on the engine (slight, but it's there). When running, volt meter on the battery reads 14.5v +/- and when not running it reads 13.3v +/-. Could this be the same corrosion issue with the regulator?

Yes. The alternator is definitely bad. Many of the aftermarket ones are just refurbished or recycled OEM ones. I have a couple of spare alternators on hand if you need one.

[Ecoman44]

The one I bought had a lifetime warranty, so let me see what I can get accomplished that route, then I'll contact you if I need one CTScott. Thanks!!

[CTScott]

The one I bought had a lifetime warranty, so let me see what I can get accomplished that route, then I'll contact you if I need one CTScott. Thanks!!

There you go - Definitely hit up the lifetime warranty.

[JimKellyfan]

Yeah, for alternators, I would check locally to see if you have a rebuilder nearby. Then, take your original and have it rebuilt, or have them install one they rebuilt. With aftermarket quality varying greatly, Napa has been up and down on quality as is with O Reilly's. But never want a pump (power steering/water/any) or (starter/alternator) electrical motor from AZ or ADV. They are mostly junk, hence the lifetime warranty.
The absolute best route is a local rebuilder, we have one in town and they are great.

[Ecoman44]

So, since I hate it when folks don't come back and report on what fixed the problem, here I am. Replaced the alternator, under warranty and at no additional cost, and all is well. We do have a shop here that I have had rebuild starters and alternators before, but I went this route as it was the quickest way for me to get my dependable mode of transport back on the road. Thanks for the help!

[WeeYari]

So, since I hate it when folks don't come back and report on what fixed the problem

+1

[Miryai]

Reviving an old post because I have a similar issue. I have an aftermarket alternator, but it's been in the car (2007 Hatchback) for over a year now with no issues until now. Occasionally, the battery light and airbag light will flash on then off (sometimes just the battery light). When it happens, I can hear a difference in the load on the engine (slight, but it's there). When running, volt meter on the battery reads 14.5v +/- and when not running it reads 13.3v +/-. Could this be the same corrosion issue with the regulator?

I hate necro'ing a thread, but it seems I'm having a similar issue.

I just replaced my alternator (I'm on my fifth one...in about 2 years.) I've replaced the battery recently. I'm getting the battery light, my airbag light and my power steering light on.

All 3 lights will go away after awhile, but whenever the power steering light comes on, even going 40mph+ the wheel will lock up, and I can't move it. It's becoming more of a safety concern now.

I've also noticed that my headlights will also be quite a bit brighter.

I've had the alternator and battery tested in the past week and everything is "functioning" as it should. All the numbers match up to what should be standard. All the mechanics I take it to, think I'm crazy, until I show them the videos I've taken of it happening.

I've also recently blown threw a new set of headlights. All 4 filaments were burnt out, but no fuses needed to be replaced.

[CTScott]

I hate necro'ing a thread, but it seems I'm having a similar issue.

I just replaced my alternator (I'm on my fifth one...in about 2 years.) I've replaced the battery recently. I'm getting the battery light, my airbag light and my power steering light on.

All 3 lights will go away after awhile, but whenever the power steering light comes on, even going 40mph+ the wheel will lock up, and I can't move it. It's becoming more of a safety concern now.

I've also noticed that my headlights will also be quite a bit brighter.

I've had the alternator and battery tested in the past week and everything is "functioning" as it should. All the numbers match up to what should be standard. All the mechanics I take it to, think I'm crazy, until I show them the videos I've taken of it happening.

I've also recently blown threw a new set of headlights. All 4 filaments were burnt out, but no fuses needed to be replaced.


Do you have any way of measuring the voltage when the car is running? You can purchase the little volt meters that plug in to the lighter outlet for about $5 on ebay, if you do not. It would be interesting to see what your alternator is putting out. From the behavior you describe it sounds like it may be running over voltage instead of under.

Are you are purchasing aftermarket alternators?

Also, have you checked the ground straps between the engine and chassis? Since the engine is mounted with bushings, those straps are the only ground for the alternator.

[Miryai]

My previous alternator was overcharging by a good bit. From what the mechanics said I was outputting like a good 19volts idling, even more with the accelerator pushed down.

Sadly, these are aftermarkets, since the dealership wants a good $2,000+ to replace the alternator, especially since the one I have is still under a lifetime warranty, but I will definitely get one of those meters, and see what happens when the battery light is on, and what not. I've not checked the straps, as I didn't think of that possibility.

Thanks for the ideas and input! I'll keep you guys posted.

[z0mb13k1ll]

my '07 with 300,000+ km still had the factory alternator on it and after a night at the drive in it started to flicker the battery light. took it to the mechanics and they replaced the battery and said it was fixed (even tho i said to them it was the alternator) and so of course i went back a week later with the same problem and a destroyed brand new battery. so got the alternator replaced and another new battery (for free).

still no idea what caused it, but it has worked fine for several months now

[Bluevitz-rs]

I'm thinking, if there's corrosion or a loose connector on the feedback wire to the alternator regulator, it might be reading the voltage as being too low and making the alternator put out maximum output.

I'd have to look at how the regulator works again in my EWD.

[CTScott]

I'm thinking, if there's corrosion or a loose connector on the feedback wire to the alternator regulator, it might be reading the voltage as being too low and making the alternator put out maximum output.

I'd have to look at how the regulator works again in my EWD.

The white wire on the alternator connector is the feedback wire to the voltage regulator. There should be battery voltage on that pin with the engine not running.

[Miryai]

I purchased a volt meter. It was $5 including shipping and handling, and you never know, it might be useful for one of my house mate's cars later. But once I have it, I'm gonna plug it in and run, see if I can manage to look at it when the issue is happening. But all I know, is that it's starting to occur a lot more frequently. It's happening more and staying on longer, than when it looks like everything is fine.

[Miryai]

Since, I hate when no one updates their problem. Voltmeter came in today. My car idles at the high 13's to low 14's. That doesn't seem to be too bad, but when the battery light comes on, it skyrockets to at least 17. I think the highest I saw was 18.3, but according to my mechanics the alternator is fine (I doubt it.). Taking it to the mechanic on Monday and telling them, and seeing if they fix it....if not, I guess I declare my car a lemon since I've replaced this damn thing four separate times already.

[CTScott]

Since, I hate when no one updates their problem. Voltmeter came in today. My car idles at the high 13's to low 14's. That doesn't seem to be too bad, but when the battery light comes on, it skyrockets to at least 17. I think the highest I saw was 18.3, but according to my mechanics the alternator is fine (I doubt it.). Taking it to the mechanic on Monday and telling them, and seeing if they fix it....if not, I guess I declare my car a lemon since I've replaced this damn thing four separate times already.

Now that you have the meter, with the engine off, check the voltage on the white pin of the alternator connector.

[Bluevitz-rs]

For what it's worth, wiggle that connector first too and see if that fixes the problem. Also after you unplug it, have a look inside for any green corrosion. There's also a chance the pin isn't tight enough.


Sent from my iPod Touch

[nortonfb]

Another return of an old thread.
My 07 hb has the battery light on.
My output is 13.5-13.8 with the fan, brights, emergency flashers, radio
and defroster. The battery is 12.8V.
The battery indicator does flicker every 5-7 seconds.
Battery is new as of 1/14.
I cleaned the ground & ground on the inner fender.
Also cleaned the positive connection.
The humidity here is high and is raining & will be until Sunday.
The car was purchased 2/14 and I have no history.
The dealer did do an inspection in February.
Ideas/thoughts?
Steve

[CTScott]

Another return of an old thread.
My 07 hb has the battery light on.
My output is 13.5-13.8 with the fan, brights, emergency flashers, radio
and defroster. The battery is 12.8V.
The battery indicator does flicker every 5-7 seconds.
Battery is new as of 1/14.
I cleaned the ground & ground on the inner fender.
Also cleaned the positive connection.
The humidity here is high and is raining & will be until Sunday.
The car was purchased 2/14 and I have no history.
The dealer did do an inspection in February.
Ideas/thoughts?
Steve

Sounds like the battery and alternator OK. Since the light is on constant, check the connector with the small wires, on the alternator to make sure it is plugged in.

[nortonfb]

I removed all the connectors and cleaned.
Where I work they have a tester
The results are:
Battery V 12.72, 618cca, rating 575cca
Starter test 11.25v
Charging test v 13.94
I still have a glowing bright red battery light, I feel so cheap..
I'm hoping that this maybe humidity related & once we dry out it will go away.
Steve

[CTScott]

I removed all the connectors and cleaned.
Where I work they have a tester
The results are:
Battery V 12.72, 618cca, rating 575cca
Starter test 11.25v
Charging test v 13.94
I still have a glowing bright red battery light, I feel so cheap..
I'm hoping that this maybe humidity related & once we dry out it will go away.
Steve

Your getting good readings. Is your alternator the original one or a replacement?

[nortonfb]

The alternator is marked Toyota Denso. I don't know if it's
original. I bought the car last February after I totaled my 08'.
Steve

[CTScott]

The alternator is marked Toyota Denso. I don't know if it's
original. I bought the car last February after I totaled my 08'.
Steve

What's the part number on it?

There is a TSB on 07-08 alternators where the internals of the voltage regulator, within the alternator, corrode.

[nortonfb]

The numbers are:
17060-21150
10 42 10 - 8180
12v / (1?) 6 6
MN
Toyota Denso
Thanks
Steve

[CTScott]

The numbers are:
17060-21150
10 42 10 - 8180
12v / (1?) 6 6
MN
Toyota Denso
Thanks
Steve

That first number should be a 2, instead of a 1 (27060-21150), but the 21150 versus 21151 is the one which potentially has the non-sealed voltage regulator, which is prone to corrosion.

[nortonfb]

If there is a TB on it, does Toyota share any cost or they
are just aware a problem exits?
Thanks much,
Steve

[CTScott]

If there is a TB on it, does Toyota share any cost or they
are just aware a problem exits?
Thanks much,
Steve

With a TB they are not required to do anything, particularly if you are out of warranty. The TBs are really just references for techs on common issues.

[Bluevitz-rs]

Is there really anything that can be cleaned or is it the IC itself that corrodes?

[CTScott]

Is there really anything that can be cleaned or is it the IC itself that corrodes?

It's a potted module. There are a couple of holes in the "bad" version and if it is bad you actually see rust at the holes. If you catch it before that you can simply seal the holes with a dab of RTV, but once corroded it is done, since you can't pull the module apart without damaging it.

[nortonfb]

Is there specs on belt tension? I mat at some pointe change it out.
Looks like a bear. I cannot see the bottom bolts, no room.
Also there is one plastic connector I cannot figure out how to remove it.
I read here some where that Bosch is not as good a Denso, I can get Bosch but not
Denso, locally.
Any truth about Bosch?
Thanks
Steve,

[Bluevitz-rs]

Maybe just try for a used one at the salvage yard and swap the chip over.


Sent from my iPod Touch

[CTScott]

Is there specs on belt tension? I mat at some pointe change it out.
Looks like a bear. I cannot see the bottom bolts, no room.
Also there is one plastic connector I cannot figure out how to remove it.
I read here some where that Bosch is not as good a Denso, I can get Bosch but not
Denso, locally.
Any truth about Bosch?
Thanks
Steve,

The belt tension is 5 mm of deflection at the long stretch. With the alternators, you want to stay away from anything other than the OEM one, as none of the aftermarket ones seem to properly drive the charge warning circuit. OEM junkyard or ebay ones are the way to go. If you go for one off an 09 you can be absolutely sure that it has the newer regulator.

[nortonfb]

I found a used one from a 2012 sedan. It's cheap enough.
But will it swap out? I can't see any reason just to swap modules.
Unless I can do it in place without removing the alternator.
Is there a DIY on this some where?
You guys are great.
Steve

[Bluevitz-rs]

Should just swap right in.


Sent from my iPod Touch

[CTScott]

I found a used one from a 2012 sedan. It's cheap enough.
But will it swap out? I can't see any reason just to swap modules.
Unless I can do it in place without removing the alternator.
Is there a DIY on this some where?
You guys are great.
Steve

It will just swap in. For doing the swap you just need a 12mm wrench for the top bolt and a 14mm for the bottom. The bottom one can be tough to get out, so if it doesn't feel like it is going to loosen easily, hit it with some penetrating oil before trying too hard. The threads are on the right side (as you are facing the engine from the bumper) so you want to hit that end specifically.

For replacing the regulator itself, here is what is involved:
http://www.yarisworld.com/forums/showpost.php?p=472705&postcount=2