Battery light

[cg716]

My battery light came on while driving. Would that indicate a problem with the battery or alternator? Battery is about 8 to 9 months old. And the alternator is about two weeks old.

[Mike Brennan]

Almost always when that happens it is the alt's voltage regulator. Take it back where you got it and they can test it. Make sure you charge it first as you may only be operating on battery. If you put it in yourself, ah well...........

[cg716]

Could it be the belt tensioner? The alternator is brand new. And tests fine in the car. So does my battery.

[cg716]

The belt is brand new as well.

[cg716]

Took the starter out. It tested fine.

[cg716]

Can the alarm system drain the battery with me not knowing. I took the fuse out for it because it started going off randomly and would not turn off.

[Mike Brennan]

It could be the belt but it would likely not be running around at all if your red light is on. If it were the belt I think you could tell by looking at it. A faulty alarm can drain the battery, but your red light came on while driving so it is a charging issue. Bad battery, bad can still test good on a 9 5 or you got a bad alternator

[cg716]

It was a bad alternator unfortunately. I just replaced it about 2 weeks ago.

[Mike Brennan]

Well that ain't fun but as I thought. Someone sold you a bad unit. It happens and there is really no way to know w/o installing it. Too bad putting it in is a little harder than on my dodge truck which takes about 6 minutes.

[Mike Brennan]

And, by the way, welcome aboard.