Stupid problem need help quick.

[RsStanG1987]

I know do a search right right. Anywho i installed underdive pullies and a new altenator on my car yesterday. Now when i use the radio or headlights when im driving the battery light comes on. Is there a simple fix for this or is it normal? Can i just put in an altenator from a newer stang?

 

[Daggar]

Put the stock pulley back on the alt if you've changed it or get an alternator overdrive pulley to install if you haven't.

 

[Foxfan88]

I remember hearing in another thread that a some 3g alt had the same size pully as the underdrive pully

 

[RsStanG1987]

So this is a common problem? Where can i get the pulley from. I mean i bought the pullys from march performance i figured there should be no problems.

 

[HISSIN50]

What is the voltage at the battery when the battery light comes on? And the voltage at the alternator's charging cable post?

What did you do wiring upgrade-wise?

Good luck.

 

[RsStanG1987]

Diddnt do any thing really just swapped pulleys. Its in the red on voltmeter.