03 Limited Battery light comes on intermittently

[nayborbob]

With engine running I measure 14.2V at the battery. With Engine off 12.8... while engine was running and 14.2V, the battery light is on! What is going on? bad ground?

Thanks for the help guys

 

[haro]

my 2003 v6 limited battery light on and at time off. when I took it to the mechanic he said is was charging good. the next day went back to the mechanic cause battery light keep coming on, this time he told me I need an alternator. got the alternator from the local toyota parts . and replaced
And problem gone.... about 2 years ago..

you need a toyota alternator

 

[nayborbob]

The alternator only has 45k miles on it.

 

[AuSeeker]

The alternator only has 45k miles on it.

Where did you get the then new(?)/rebuilt(?) alternator from and what brand is it, who did the install?

It could be that the wiring/connections are getting loose and or corroded, check and clean all connections making sure they are all making a good connection and are tight and see if that fixes your issue, if not then go to the next step below.

The alternator could still be or going bad, the internal voltage regulator could be going bad, a multimeter voltage testing is the first step in determine that, BUT proper testing equipment is required to test the alternator under various RPMs and load to truely determine the condition of the alternator, take it to at least 2 or more auto parts stores and have them test the alternaotr properly and see if they all come to the same conclusion.