Yaris battery light on...why??

[spolice973]

took it to autozone, but we can't determine the cold cranking amps on the battery. i have a 2007 yaris hb, since 2006 (about 105k miles on it). the car starts, the radio runs, the lights work fine, but the battery light is on (red - which indicates to go to dealer - which is closed today, of course). how can the light be on but the car runs fine? does anyone know the cc amps on the original battery? not in manual, on their website or anywhere! amazing, i've found the one thing google can't find!

thanks...

[silver_echo]

normally, that light only comes on when one of three things is bad... target the battery, should be ~500cca IIRC... the second option is to check the alternator... third is to check your battery connections for corrosion... one other possibility, that autozone people might miss, is the serpentine belt there?

[Altitude]

Maybe your alternator is having a problem.

[why?]

i didn't even know there was a battery light. That is just weird.

[silver_echo]

i didn't even know there was a battery light. That is just weird.

all cars that i have ever come across have one... comes on when you first turn the car on, then turns off when the alt. picks up...

[CTScott]

There's a known/common problem with 07-08's with the voltage regulator within the alternator corroding and casing the light to come on.

[BLH]

Here is the TSB for the 2007.

http://www.etimago.com/yaris/TSB/T-EL002-07(Charging%20System%20Warning%20Light%20ON%20).pd f

[silver_echo]

There's a known/common problem with 07-08's with the voltage regulator within the alternator corroding and casing the light to come on.

another very likely answer... and one that i will bank on as scott does more with yaris than i do...


go with scott's answer for the time being, and if that is not it, then we follow the trouble tree...

[spolice973]

i dont plan to drive it anymore today...and my mechanic, thankfully, is half block away. i will have to go first thing in AM. even though autozone does free testing, i'm afraid to drive it back there (a couple miles away) and have it conk out on me.

[silver_echo]

i would mention the TSB about the voltage regulator to the mechanic... might save him some time...

[spolice973]

i also plan to ask him why this wasn't seen (if it is indeed corrosion) when i had my 100k tune up

[CTScott]

i also plan to ask him why this wasn't seen (if it is indeed corrosion) when i had my 100k tune up

He would only have seen it if he completely disassembled the alternator. There's a thread on here where I posted pictures of one completely disassembled.

[spolice973]

He would only have seen it if he completely disassembled the alternator. There's a thread on here where I posted pictures of one completely disassembled.

ok...thank you for saying that b/c i like this guy and i'd hate to think he's screwing me over or missing things! ok, so i will be nice :)

i'll report back in the afternoon with any findings...i hope i can drive it to work- shoot!

[WeeYari]

I've been dealing with this for nearly 3 years with my '06.

Whenever there is a heavy rainfall, or very dense fog, my battery light comes on. It willl always go out again when conditions dry up. I have a spare alternator on stand-by just waiting for the day the voltage regulator finally gives up for good. Had the spare for almost a year now but the original just wont die.

BTW, is your light on solid, or does it flicker? Mine flilckers. If it is on solid, then you may actually have another issue other than the regulator.

[Thegg]

I have the same car and the same issue. I'm pretty certain that it's the Voltage Regulator. Can anyone recommend a good site to order from?