I NEED YOUR INPUT/HELP! PLEASE, Can an alternator drain a battery with car off? Options

[Random_Stranger]

Ok so I have this issue where my car battery is suddenly being drained by something. I was just wondering what first things to look at. Also what I find strange is that it didn't want to start last night (I witnessed a hit and run across the street, thought the guy was gonna stop but when he took off, I was going to jump in my car and get his license plate number, but my car didn't start). So I busted out the voltmeter and seen it was like at 9.38v. I set my alarm and went inside and later that night, I hear my alarm chirping in a way I never heard before. Then it got louder, and louder and then just went off making it's normal sound if someone attempted to break in. So I go out there and disarm it. Noticed my lights were dim and checked the reading again. It was 7.38v. I left the voltmeter connected to it and sat in the car wondering what it could be. I went back and noticed it climbed up a bit to 7.44v. I let it sit there and watched and it climbed up to 7.48v before I just disconnected it.

Is that normal for a voltmeter to do that? You think it might be my car alarm? I have an optima battery which is like 3 years old. Not sure what the life expectancy is on those or if maybe it is in fact something draining power.

This post has been edited by Random_Stranger: Jan 9, 2012 - 4:39 PM

[Smiles98]

if you disconnected the wires to the alternator and the light went out than it has to be the alternator. the wires leaking would have kept the light on. It has to be the alternator. clean the connectors up with some sandpaper and use (dio-electic compound) when re-installing to prevent corrosion "that green stuff". you can get this at any auto zone or car parts store they sell it for installing light bulbs.

Hope this helps.

[Random_Stranger]

if you disconnected the wires to the alternator and the light went out than it has to be the alternator. the wires leaking would have kept the light on. It has to be the alternator. clean the connectors up with some sandpaper and use (dio-electic compound) when re-installing to prevent corrosion "that green stuff". you can get this at any auto zone or car parts store they sell it for installing light bulbs.

Hope this helps.

Ok thanks. I just never heard of an alternator robbing the battery of voltage before. I heard about autozone alternators doing that from other forums and what others posted when I did a search, I just wanted to verify from others, since it was something I wasn't aware of.