Help please, battery light issue..

DukesI3

New Member
Established Member
Joined
Jan 21, 2005
Messages
23
Location
Nashville
Hey guys, I purchased an 03 vert about a month ago. A few days ago i noticed the battery light on start up, it would quickly turn off after a minute or two of driving. Today, the light stayed on the entire drive to work (25 minutes). So i decided I'd get it tested on my way home. Unfortunately I didn't make it 5 minutes into my trip after work, there's an AF ratio gauge that i've got.. It started blinking at me telling me i was dipping to about 7.5. Shortly after my abs light came on and the car started sputtering. I stopped and shut the car off.

A buddy of mine picked me up and brought me to the closest place I could grab a battery from. I had a feeling it was not the battery, but the alternator starting to fail. We dropped the battery in it and fired it up, battery light still on. I ended up deciding to try to make it home with the fog lights on to lighten the drain and made it. I'm wondering if there's and obvious answer here, I'm far from being a mechanic, i assumed it was the alt if the battery wasn't the issue.. but after research I'm seeing that maybe it's the regulator? Do these symptoms combined point to one over the other? The AF ratio thing threw me off a little bit?

Thanks for any replies!
 

Coxy

Active Member
Established Member
Joined
Jun 21, 2014
Messages
362
Location
Kootenays BC, Canada
Have the charging system checked. Bad battery can/will take out the alternator, and over time, alternator will beat down the battery. Vicious cycle. Improper charging/supply voltage will through all the electronics, wideband gauge is no different.
You need to start there, but it does sound pretty textbook.
 

svtshadow

Banned
Joined
Feb 6, 2013
Messages
1,521
Location
deadcity
Change alternator. That is your problem. Just went through this 3 weeks ago. Changed alternator and all is good in the hood!
 

Bigggy

Member
Established Member
Joined
Feb 25, 2013
Messages
648
Location
Québec/Canada
Alternator as usually with cobras... 90% when the battery light light up it's the alternator and not only in cobras/mustang in pretty much every cars.
 
Last edited:

c6zhombre

E85 NutSwinger
Established Member
Joined
Sep 14, 2008
Messages
5,430
Location
League City, TX
Have the charging system checked. Bad battery can/will take out the alternator, and over time, alternator will beat down the battery. Vicious cycle.


+1

I cringe at some of the threads where people seem determined to stretch a battery well past it's life span. "I just charged it overnight...seems ok now. The car started, must be all good..." Uuuuu, no it's not, you've just entered the grips of the vicious cycle and a future thread on "I have a dead alt..." is sure to follow


There comes a point a new battery, a new alt, and a desulfating maintenance charger is just a great idea. Happy battery, happy alt, happy owner. No more being stranded.
 

apex svt

MEAN STREAK
Established Member
Joined
Jun 29, 2012
Messages
2,167
Location
USA
turn the key on without starting it and hold a wrench to the alternator pulley, if its no magnetic alt is usually garbage.
 

Users who are viewing this thread



Top