Check engine light

[ho1ywars]

was teaching a friend how to drive stick last night, and during the process the check engine light came on. After i dropped her off, i pull in my driveway and put all my windows up and my sunroom up to go inside for the night. While doing it i noticed the volt meter droooooopppeddd hard, right down to the line its borderline red. i dont remember seeing this before, was wonderiong if it was comon in probes. if its not normal its the alternator or the battery right? Would the alternator going cause the light to come on...

[WhiteXFire]

Yeah, I had that happen before in my old car. You hold the button for the power windows or something and the volt meter significantly jumps. I'd get it looked at soon so if it's the alternator and not the battery you don't end up having to replace both.

[ho1ywars]

is there anyway i can check it...
and if i get a code reader on it, will it spit out a code telling me its the alternator...

[SilverTurboRidin]

negative i dont think it will....you can get rebuilt alt's for real cheap look into it

[piratius]

Easier way to do it...

Get a voltmeter, find the alternator ground wire & the power wire. Check the voltage. It should be ~13. If it is, have a friend load the engine (windows/headlights/whatever) If it's still 12+, then it's not the alternator. If it does go down, expect to spend time working on it :)

What year probe do you have? I had a 94 GT for a while.

~Brad