Battery light issues

98stangv8

Active Member

Oct 3, 2003

1,036

0

36

fayetteville, nc

May 9, 2009

#1

• May 9, 2009

• #1

I originally posted this in talk by accident...


My red battery light just started coming on...when the car is off...I am getting 13 volt reading...when at idle...12...the light still isn't coming on yet...

but when I rev it...even a little bit, such as on the throttle body under the hood, the light will come on and the voltmeter drops down into the 11's...

battery or alternator? I just had a new alternator put on a year or so ago...

What other tests to run besides taking off the alternator and having it tested?

Thanks!

 

98stangv8

Active Member

Oct 3, 2003

1,036

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36

fayetteville, nc

May 9, 2009

#2

• May 9, 2009

• #2

Ok..new finding...the light only comes on when I go above 2000 rpms...once I go below that..the light goes back off...

Anyone?

 

Pearl02

Member

Nov 27, 2004

496

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16

Kansas City

May 10, 2009

#3

• May 10, 2009

• #3

I'm leaning towards the alternator or the regulator. You can drive up to an auto parts store to check the battery out. That will atleast rule it out if it's ok. Ofcourse, the regulator is built into the alternator now days. What the condition of the belt? If it's slipping that could cause some problems with the alternator. Pearl02.

 

98stangv8

Active Member

Oct 3, 2003

1,036

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36

fayetteville, nc

May 10, 2009

#4

• May 10, 2009

• #4

Hey,

Brand new belt...just put on about a month ago...

It all started once I got a new fan on...never had an issue before...thought maybe the fan was sucking more power now...that the car wasn't used to providing before?

 

Pearl02

Member

Nov 27, 2004

496

0

16

Kansas City

May 10, 2009

#5

• May 10, 2009

• #5

I can't imagine a electric fan causing the problem. I know that the fans do pull some current while running. Do you have any large amps or audio system? That stuffs pulls monster power. maybe your alternator isn't able to keep up with things. Pearl02.

 

98stangv8

Active Member

Oct 3, 2003

1,036

0

36

fayetteville, nc

May 10, 2009

#6

• May 10, 2009

• #6

Pearl02 said:

I can't imagine a electric fan causing the problem. I know that the fans do pull some current while running. Do you have any large amps or audio system? That stuffs pulls monster power. maybe your alternator isn't able to keep up with things. Pearl02.

Click to expand...

I don't even have the radio on and it occurs...

The thing I don't understand...It only happens when I hit 2000 rpms...even in park/neutral...If I rev it to 2k...light comes on...

Once it gets below 2k, light goes back off...