battery light stays on but running fine

[Starhawk]

many thing could happen to your car, when your battery is weak. Recently, my 2007 Yaris had gas pedal had no power when I stepped on it. When I took to a mecahnic, he suugested me to change the air filter which I did and there was no change on the gas pedal, so he suugested me to take to the dealer, the guy said to me that the technician will need at least an hour to look for any problem. WhenI got home, i got a call from the dealer, he said to me that because I was having an after market remote starter installed in my car, which causes the problem, he said that the Toyota experienced technician will have to check all the wiring, and run them again which he will need another three hours to do so, and each hour will cost me $110.00+ Tax. Which will total about four hours. By evening, I went to the dealer, the service agent said to me that my car had a serious problem, which the technician had to spend more time to check all the electrical wiring and so on, But the tests are ok and the car has power on the gas pedal, and he also told me that the battery is weak and I needed to replace the battery.... It costed me $497.00 and change just for that( istead of saying, we checked the battery and found it was very weak and needed to replacedand if that was the case, it wouldn't have costed me $497.00). I believed that for any problem we have with our cars, and if we take to the dealers, they know what the problem is ,but they just wanted to make as if very hard to find and charge us more.

[sambo42xa]

My 2007 (99k) is pretty much doing the same thing. Only differance: car is running at idle and the battery light flutters not to the point it goes out. While running I remove either battery cable or even both and the battery light stays on and does not flutter (car is still running). Put the cable/s back on and the light flutters again.
With car off I removed the battery cable off of the alternator and cleaned the connection since it did have a little bit of corrosion. The pin plug I removed also but did not see any corrosion. Output on alternator was around 13.8 and the same at the battery. No change after cleaning connection.
From what I have read here, it seems you folks are steering more towards the alternator (internals) than the battery. No problems starting car so I'm pretty sure the battery is fine (13.8 volts). Everything else works fine. Are there any readings on the pins I can check or are we 99.9% sure it is the alternator?
I'm good with mechanics and I'll check/test whatever.
Thnx in advance!
sambo

[CTScott]

Originally Posted by sambo42xa

My 2007 (99k) is pretty much doing the same thing. Only differance: car is running at idle and the battery light flutters not to the point it goes out. While running I remove either battery cable or even both and the battery light stays on and does not flutter (car is still running). Put the cable/s back on and the light flutters again.
With car off I removed the battery cable off of the alternator and cleaned the connection since it did have a little bit of corrosion. The pin plug I removed also but did not see any corrosion. Output on alternator was around 13.8 and the same at the battery. No change after cleaning connection.
From what I have read here, it seems you folks are steering more towards the alternator (internals) than the battery. No problems starting car so I'm pretty sure the battery is fine (13.8 volts). Everything else works fine. Are there any readings on the pins I can check or are we 99.9% sure it is the alternator?
I'm good with mechanics and I'll check/test whatever.
Thnx in advance!
sambo

The blue wire on the multi pin connector on the alternator is the output to the cluster that drives the indicator. The service manual says that the normal operating range is 11 to 14 volts, so you could measure the voltage on that wire to see if it is fluctuating. The pink wire is a signal to the ECM and AC ECU. Based on the output of this signal, the ECM can tell the cluster to also light the indicator.

There is a TSB for 07 Yaris about a potential internal corrosion issue of the voltage regulator, which can cause the behavior that your are seeing, without actual charging issues.

[sambo42xa]

CTScott- I was just informed this evening from my wife that the Battery Light went out. Though she didn't notice if it was out when she started the car or if it went out while driving.....either way I will take reading/s off of these pins tomorrow and see what I come up with so I know for myself what to look for next time. And this willl help for Others on the forum which is what it's all about, right?
.......too be continued...........
thnx, sambo
southern, nh
30* with intermittent clouds

[roadrunner]

Originally Posted by Starhawk

many thing could happen to your car, when your battery is weak. Recently, my 2007 Yaris had gas pedal had no power when I stepped on it. When I took to a mecahnic, he suugested me to change the air filter which I did and there was no change on the gas pedal, so he suugested me to take to the dealer, the guy said to me that the technician will need at least an hour to look for any problem. WhenI got home, i got a call from the dealer, he said to me that because I was having an after market remote starter installed in my car, which causes the problem, he said that the Toyota experienced technician will have to check all the wiring, and run them again which he will need another three hours to do so, and each hour will cost me $110.00+ Tax. Which will total about four hours. By evening, I went to the dealer, the service agent said to me that my car had a serious problem, which the technician had to spend more time to check all the electrical wiring and so on, But the tests are ok and the car has power on the gas pedal, and he also told me that the battery is weak and I needed to replace the battery.... It costed me $497.00 and change just for that( istead of saying, we checked the battery and found it was very weak and needed to replacedand if that was the case, it wouldn't have costed me $497.00). I believed that for any problem we have with our cars, and if we take to the dealers, they know what the problem is ,but they just wanted to make as if very hard to find and charge us more.

Sorry to hear your story. Being that it is a 2007 Yaris battery, it is time to get a new one. That is free info. I still am running my 2007 original battery.