Notices
Evo General Discuss any generalized technical Evo related topics that may not fit into the other forums. Please do not post tech and rumor threads here.
Sponsored by: RavSpec - JDM Wheels Central

bad alternator or battery?

Thread Tools
 
Search this Thread
 
Old Oct 31, 2011, 07:28 PM
  #1  
Newbie
Thread Starter
iTrader: (1)
 
bbak11010's Avatar
 
Join Date: May 2008
Location: Atlanta GA
Posts: 73
Likes: 0
Received 0 Likes on 0 Posts
bad alternator or battery?

hey guys,
I posted a few hours ago for battery question.. but I guess I need to also consider if my alternator is going bad.
About a week ago, I finished installing my audio system, then two days ago I went into a store for 30 minutes and car was dead. I had it jumped and drove another 2 hours to home. Then yesterday morning I tried to start her and it was dead again. I guess I can jump it again to go to autozone and check the battery for free, but do they also have a tool to check my alternator?
Any help is appreciated!
Old Oct 31, 2011, 07:33 PM
  #2  
Evolved Member
iTrader: (35)
 
wizzo 8's Avatar
 
Join Date: Mar 2005
Location: Chicago suburbs
Posts: 3,821
Received 11 Likes on 9 Posts
If its running ok after jumping it then is probably just the battery. If you take the jumper cables off and the car dies then it has a bad alternator
Old Oct 31, 2011, 07:38 PM
  #3  
Evolved Member
iTrader: (7)
 
HornstarBU's Avatar
 
Join Date: Sep 2003
Location: Austin, Tx
Posts: 1,509
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by wizzo 8
If its running ok after jumping it then is probably just the battery. If you take the jumper cables off and the car dies then it has a bad alternator
This ^ (and sometimes a loose cable can cause this oddness)

Plus, yes autozone can test your battery and alternator.

Also, you gots a stick, you don't need someone to jump you! Roll start that bugger...I did it this weekend when my battery died.

Also, Sears sells Diehard batteries, I always buy Diehard gold. About 100 bucks, warranty for 3 years though, and if you take it back in before 3 years because it failed, they replace the battery and start the warranty all over again.....They even gave me a gift card with 25 bucks on it because I paid 125 2.5 years ago, but they were on sale now for 100. I love sears...
Old Oct 31, 2011, 07:41 PM
  #4  
Evolved Member
iTrader: (16)
 
blknblubkrdude's Avatar
 
Join Date: Feb 2010
Location: Gillette, WY
Posts: 681
Likes: 0
Received 0 Likes on 0 Posts
A simple $5 multimeter from harbor freight will help you diagnose your problem.

Touch both battery terminals with the leads and record the DC voltage reading.

It sounds like a battery to me.

Yes the parts store will have the tools to diagnose.
Old Oct 31, 2011, 07:43 PM
  #5  
Evolving Member
iTrader: (35)
 
BoostIsMyDrug's Avatar
 
Join Date: Feb 2009
Location: Hershey, PA
Posts: 224
Likes: 0
Received 0 Likes on 0 Posts
Sounds like just a bad battery. You can check the alternator yourself if you have a multimeter. Start the car, or jump it, and attach the multimeter to the positive and negative of the battery. This will show you the voltage that the alternator is making. 14v is the money zone. Even 13.8v+ will pass on most testing machines.

If you also would like, jump the car and take it to an Advance Auto Parts. They will test the battery and alternator for free. Takes about 5 min and they will also give you a print out of the results.

Good luck. Start pricing an Optima battery now, as that sounds like your problem.
Old Oct 31, 2011, 07:50 PM
  #6  
Newbie
Thread Starter
iTrader: (1)
 
bbak11010's Avatar
 
Join Date: May 2008
Location: Atlanta GA
Posts: 73
Likes: 0
Received 0 Likes on 0 Posts
thanks guys for your comments. I will try to check the battery with my multimeter and see what i come up with. Also, i'm leaning towards the Diehard plats for my next battery.
Old Oct 31, 2011, 08:08 PM
  #7  
Evolving Member
iTrader: (15)
 
jnut24's Avatar
 
Join Date: Jun 2009
Location: wa
Posts: 148
Likes: 0
Received 0 Likes on 0 Posts
sounds like a draw....something you installed is still drawing power, to cause your battery to go dead. i would start by unhooking your system that you installed first or while the car is off test the battery. should have 9.5-12v's then do it while its running and that will be your alternator reading. should be between 13.5-14.5volts any more or less is bad.
Old Nov 1, 2011, 06:01 AM
  #8  
Evolved Member
iTrader: (7)
 
HornstarBU's Avatar
 
Join Date: Sep 2003
Location: Austin, Tx
Posts: 1,509
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by jnut24
sounds like a draw....something you installed is still drawing power, to cause your battery to go dead. i would start by unhooking your system that you installed first or while the car is off test the battery. should have 9.5-12v's then do it while its running and that will be your alternator reading. should be between 13.5-14.5volts any more or less is bad.
I was guessing his audio system was putting more strain on the battery and caused it to fail, but...what kind of stuff did you install? Amp? wired to what and how, like jnut is somewhat asking.

Easy multimeter test would be run the car, check voltage, if it's 14, but when you cut it off it goes to like 8v you know it's the battery. If it's 14....then slowly drops to 12...10...8 over time, something is draining it.
Old Nov 1, 2011, 06:18 AM
  #9  
Evolved Member
iTrader: (25)
 
GTijoejoe's Avatar
 
Join Date: May 2008
Location: Ohio
Posts: 2,110
Likes: 0
Received 11 Likes on 11 Posts
Originally Posted by jnut24
sounds like a draw....something you installed is still drawing power, to cause your battery to go dead. i would start by unhooking your system that you installed first or while the car is off test the battery. should have 9.5-12v's then do it while its running and that will be your alternator reading. should be between 13.5-14.5volts any more or less is bad.
good thought, normally things like this arn't coincidences
Old Nov 1, 2011, 07:03 AM
  #10  
Evolved Member
iTrader: (2)
 
mshilto89's Avatar
 
Join Date: Jan 2011
Location: Minnesota
Posts: 534
Likes: 0
Received 1 Like on 1 Post
Turn the car on, run it for 15 minutes, after that pop the hood and take off the battery cables. If it continues to run it is the battery, if it starts sputtering or shuts off completely, it is the alternator.

Also when I had my 04 Ram HEMI pickup I was running an 800 watt Fosgate amp and noticed whenever the bass hit the lights would dim a bit. This was because it was over loading the alternator. So depending on what kind of system you have (power wise) you have to be weary on how much power you have draining from the electrical system. If 800 watts can push a full size pickup to the max imagine what it can do to the teeny alternator on the Evo.
Old Nov 1, 2011, 07:49 AM
  #11  
Evolved Member
iTrader: (35)
 
wizzo 8's Avatar
 
Join Date: Mar 2005
Location: Chicago suburbs
Posts: 3,821
Received 11 Likes on 9 Posts
Originally Posted by mshilto89
Turn the car on, run it for 15 minutes, after that pop the hood and take off the battery cables. If it continues to run it is the battery, if it starts sputtering or shuts off completely, it is the alternator.
Altough this does work its not good for your alternator. If you do this make sure all the accesoris are off so the alternator doesnt get hit with a big load.
Old Nov 1, 2011, 07:53 AM
  #12  
Evolved Member
iTrader: (2)
 
mshilto89's Avatar
 
Join Date: Jan 2011
Location: Minnesota
Posts: 534
Likes: 0
Received 1 Like on 1 Post
Originally Posted by wizzo 8
Altough this does work its not good for your alternator. If you do this make sure all the accesoris are off so the alternator doesnt get hit with a big load.

I figured it would be kind of a do or die thing. Mechanic taught me this years ago and has worked every time. But yes, make sure everything is off.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
kindaloweredlif
Lancer Troubleshooting
2
May 9, 2017 07:14 PM
Verlassene
Evo Engine / Turbo / Drivetrain
6
Dec 7, 2015 11:04 PM
hooliganSKATE
Evo General
6
Jul 16, 2015 06:21 AM
simplecomplex
Lancer Troubleshooting
0
Jan 3, 2012 01:24 PM
hiimwayne
Evo General
19
Jan 30, 2010 06:54 PM



Quick Reply: bad alternator or battery?



All times are GMT -7. The time now is 04:44 AM.