IT IS DYING

S

spade33

New Member

Nov 14, 2006

198

0

0

Tempe, Arizona

Dec 11, 2006

#1

• Dec 11, 2006

• #1

So i need a little advice on what would be making my car battery die if it sits for a few hours? i have a 66 mustang it has a new batery and a 289 in it i dont really know what it could be so any advice would be great thank you alot guys & girls :SNSign:

 

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5.0ina66

Member

Jun 6, 2003

664

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16

Ohio

Dec 11, 2006

#2

• Dec 11, 2006

• #2

Well, is it charging? Most cars like ~14V get em started.

 

krash kendall

Active Member

Nov 19, 2004

1,258

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36

Aldergrove, B.C. Canada

Dec 11, 2006

#3

• Dec 11, 2006

• #3

You may have a short in the electrical system. Put a test light or meter between the ground post on the battery and the battery terminal. If you show any current flow, start taking out the fuses one at a time untill the light is off or the meter reads zero, then you will know which curcuit is the problem.

 

70dvr

New Member

Jul 25, 2006

46

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0

Brandon, Florida

Dec 11, 2006

#4

• Dec 11, 2006

• #4

Last year I bought a Wal-Mart battery that lasted 3 months. The one it replaced had lasted 8 years. I tested it by disconnecting it, charging it. Then checking the voltage. After 12 hours it was down to 11 volts. Just saying that you cannot trust a battery just because it's new.
I need to buy a battery load tester. Sears has them for 60 bucks.

 

geostang351

Member

Mar 30, 2005

946

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17

Danb., CT

Dec 11, 2006

#5

• Dec 11, 2006

• #5

krash kendall said:

You may have a short in the electrical system. Put a test light or meter between the ground post on the battery and the battery terminal.

Click to expand...

Can you explain this a little better, please.

 

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danny clemens

Member

May 4, 2005

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16

Dec 11, 2006

#6

• Dec 11, 2006

• #6

A defective voltage regulator can cause a battery to discharge.

 

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danny clemens

Member

May 4, 2005

728

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16

Dec 11, 2006

#7

• Dec 11, 2006

• #7

double post

 

krash kendall

Active Member

Nov 19, 2004

1,258

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36

Aldergrove, B.C. Canada

Dec 11, 2006

#8

• Dec 11, 2006

• #8

geostang351 said:

Can you explain this a little better, please.

Click to expand...

Let's say for example you have a short in your courtesy light system. The curcuit is drawing power continuously from the battery even with the doors closed (for this example the lights don't work at all). If you put a test light or meter in line with the negative battery terminal the test light should come on dimly (depending on how bad the short is) or the meter will show current flow. If you remove the fuses one a time and you still read a draw, you are eliminating those curcuits as the culprit. You eventually pull the fuse labled "dome" and voila! The meter reads no draw or the test light goes out. You now know the problem lies in the dome/courtesy light curcuit.

 

geostang351

Member

Mar 30, 2005

946

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Danb., CT

Dec 11, 2006

#9

• Dec 11, 2006

• #9

Sorry, I mean to ask, where do the contacts touch for the light/meter? Your first explaination stated, "between the ground post on the battery and the battery terminal". I just not sure where I would place my meter leads; on both battery posts?

 

GoinBroke

New Member

Jul 13, 2006

109

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0

Joliet, Il

Dec 11, 2006

#10

• Dec 11, 2006

• #10

I disconnected the ground cable and put one end of the meter on the neg post and the other on the cable. This puts the test light or meter inline to show the voltage use.

 

allcarfan

The Answer Man

Founding Member

Apr 8, 2001

2,458

1

56

North Atlanta

Dec 11, 2006

#11

• Dec 11, 2006

• #11

First things first...make sure all of your connections are good. Secondly, go have your alternator tested. If you are still good there...time to start tracking down a short.

 

krash kendall

Active Member

Nov 19, 2004

1,258

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36

Aldergrove, B.C. Canada

Dec 11, 2006

#12

• Dec 11, 2006

• #12

GoinBroke said:

I disconnected the ground cable and put one end of the meter on the neg post and the other on the cable. This puts the test light or meter inline to show the voltage use.

Click to expand...

What he said. The terminal is the part on the cable, the post is the part on the battery. The light or meter goes inline.

If this doesn't help then the short is between the engine bay and the fuse block, so you would have to start dissconnecting devices in front of the firewall.

I guess the first thing to do that has been overlooked is to make sure you're getting 12.5V at the battery with the car off and +/- 14.4V with the car running.

 

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spade33

New Member

Nov 14, 2006

198

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0

Tempe, Arizona

Dec 11, 2006

#13

• Dec 11, 2006

• #13

thanks for all the information its gunna be hard to reply to all of them and from the looks of it someone else is having the same problem as me haha well it is charging cuz i can jump it and itll be fine to run untill i let it sit. so as far as i can tell the alternator is working i know this was just an example but the courtesy lights dont work in my car and i beleive one of hte pushers on the door that would shut off the lights is broken of so they may be drawing power constantly but ill have to check using the test light i think the guy liing next to me has one

 

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5.0ina66

Member

Jun 6, 2003

664

0

16

Ohio

Dec 11, 2006

#14

• Dec 11, 2006

• #14

First you need to make sure it's charging. To do that, put a voltmeter on the battery with the car idling. Look for 13-14.8V there. You also might need to see if there's anything coming out of the alt and to do that, you need to put a voltmeter on the S terminal on the back and look for 13-14.8v at idle.

Then, you can look for wiring problems, bad regulator, etc if you haven't found the problem already.

I think some posters are jumping the gun, start with the basics and go from there.