dead battery
Thread Starter
Intermediate
Joined: Mar 2009
Posts: 26
Likes: 0
From: rochester ny
dead battery
my battery was dead today,,,,last time i drove my 1980 vette was 2
weeks ago,,,i have charged it several times since november when i
bought the car,,i know that i should get the battery load tested at parts
store..but does any one know where some possible power drains are?
weeks ago,,,i have charged it several times since november when i
bought the car,,i know that i should get the battery load tested at parts
store..but does any one know where some possible power drains are?
Le Mans Master
Joined: Apr 2001
Posts: 5,000
Likes: 1
From: Minneapolis, Mn USA
Is your battery a good battery? Maintenance free or can you check the cells for fluid level?
If you've ruled out the usuall suspects of dome light delay and glove box light, try the alternator or even the starter.
I think a bad diode in your alternator can be a source of a battery drain. I would charge it up, use a DC ammeter on your digital voltmeter and measure the current draw with the DMM making connection to the battery negative cable. Unplug the alternator charging wire and see if your draw goes away.
I believe I have heard of a bad starter solenoid causing a current draw. Disconnect the solenoid wire on the solenoid and see if your draw goes away.
If nothing helps, start pulling some fuses to isolate the problem. Get the Helms GM service manual for your year to help you.
B.
If you've ruled out the usuall suspects of dome light delay and glove box light, try the alternator or even the starter.
I think a bad diode in your alternator can be a source of a battery drain. I would charge it up, use a DC ammeter on your digital voltmeter and measure the current draw with the DMM making connection to the battery negative cable. Unplug the alternator charging wire and see if your draw goes away.
I believe I have heard of a bad starter solenoid causing a current draw. Disconnect the solenoid wire on the solenoid and see if your draw goes away.
If nothing helps, start pulling some fuses to isolate the problem. Get the Helms GM service manual for your year to help you.
B.
Le Mans Master
Joined: Jan 2007
Posts: 8,012
Likes: 3,343
From: Omaha NE
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Before anything else I'd put a full charge on that battery & take it in for a load test. You might get lucky.........
Drifting
Joined: Apr 2008
Posts: 1,992
Likes: 56
From: Antioch IL
Is your battery a good battery? Maintenance free or can you check the cells for fluid level?
If you've ruled out the usuall suspects of dome light delay and glove box light, try the alternator or even the starter.
I think a bad diode in your alternator can be a source of a battery drain. I would charge it up, use a DC ammeter on your digital voltmeter and measure the current draw with the DMM making connection to the battery negative cable. Unplug the alternator charging wire and see if your draw goes away.
I believe I have heard of a bad starter solenoid causing a current draw. Disconnect the solenoid wire on the solenoid and see if your draw goes away.
If nothing helps, start pulling some fuses to isolate the problem. Get the Helms GM service manual for your year to help you.
B.
If you've ruled out the usuall suspects of dome light delay and glove box light, try the alternator or even the starter.
I think a bad diode in your alternator can be a source of a battery drain. I would charge it up, use a DC ammeter on your digital voltmeter and measure the current draw with the DMM making connection to the battery negative cable. Unplug the alternator charging wire and see if your draw goes away.
I believe I have heard of a bad starter solenoid causing a current draw. Disconnect the solenoid wire on the solenoid and see if your draw goes away.
If nothing helps, start pulling some fuses to isolate the problem. Get the Helms GM service manual for your year to help you.
B.
you can also disconnect the negative terminal and with one of those circuit tester make a bridge between the negative terminal and the negative battery cable you disconnected. when you make sure the dome light is off and the light on the testers should be off. if the light on the tester is on, start to pull the fuses to find out where the draw is.
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Safety Car
Joined: Sep 2007
Posts: 4,458
Likes: 331
From: Indy Indiana
test your milliamp draw with the doors closed and the lights off and the key out.. you should see some draw.. for your clock and radio memory and any other aftermarrket assessories.. you should see 10-20 milliamp draw, a dome light will draw 1700 milliamps.. a stuck dome light will kill your battery in a day.. as stated a rectifier may be bad n your alternator.. check your continuity from alternator power lead to ground, there should be none...
and finally and most likely your problem... your battery is probably bad... it will hold a charge for a day or 3 to start the car, but some cels are probably weak and it won't hold the charge for more than that time... 3 year old batteries lose about 50% capacity..
I had the same problem, my car would not start if left for a week.. so I bought the biggest and most cold cranking amp battery I could find...... as a result now, it started this spring easilly after being shut down for 2 months...
if your battery is old.. go get you a new one... if it is 3 years old or more, you need one anyway..
and finally and most likely your problem... your battery is probably bad... it will hold a charge for a day or 3 to start the car, but some cels are probably weak and it won't hold the charge for more than that time... 3 year old batteries lose about 50% capacity..
I had the same problem, my car would not start if left for a week.. so I bought the biggest and most cold cranking amp battery I could find...... as a result now, it started this spring easilly after being shut down for 2 months...
if your battery is old.. go get you a new one... if it is 3 years old or more, you need one anyway..
Pro
Joined: Feb 2007
Posts: 548
Likes: 1
From: Victoria VA
test your milliamp draw with the doors closed and the lights off and the key out.. you should see some draw.. for your clock and radio memory and any other aftermarrket assessories.. you should see 10-20 milliamp draw, a dome light will draw 1700 milliamps.. a stuck dome light will kill your battery in a day.. as stated a rectifier may be bad n your alternator.. check your continuity from alternator power lead to ground, there should be none...
and finally and most likely your problem... your battery is probably bad... it will hold a charge for a day or 3 to start the car, but some cels are probably weak and it won't hold the charge for more than that time... 3 year old batteries lose about 50% capacity..
I had the same problem, my car would not start if left for a week.. so I bought the biggest and most cold cranking amp battery I could find...... as a result now, it started this spring easilly after being shut down for 2 months...
if your battery is old.. go get you a new one... if it is 3 years old or more, you need one anyway..
and finally and most likely your problem... your battery is probably bad... it will hold a charge for a day or 3 to start the car, but some cels are probably weak and it won't hold the charge for more than that time... 3 year old batteries lose about 50% capacity..
I had the same problem, my car would not start if left for a week.. so I bought the biggest and most cold cranking amp battery I could find...... as a result now, it started this spring easilly after being shut down for 2 months...
if your battery is old.. go get you a new one... if it is 3 years old or more, you need one anyway..
thanks
Intermediate
Joined: Mar 2009
Posts: 35
Likes: 0
Mn-Brett has got it pegged. A bad diode in the Alt. will drain the battery overnite. Very easy to repair and cheap if you buy your parts at a starter rebuild shop. I rebuilt the one on my 78 last year. Brushes, diode and regulator was around $7.00. Parts house is about $22.00 for the same parts.
Drifting
Joined: May 2007
Posts: 1,491
Likes: 2
From: North Royaton Ohio
Here's your answer
I got a real easy way to tell if you're drawing current. With the door closed and making sure all interior lights are off (therefore drawing no current) SLOWLY disconnect the negative battery cable. If you get any sparks between the terminal and the cable, you're pulling current somewhere. Then you can follow all of the advice given by all the other guys. If you don't have any sparks, get yourself a new battery.
Safety Car
Joined: Jun 2004
Posts: 4,652
Likes: 80
From: Lakeland Florida
I would agree with the person that asked about the age of the battery.
Depending on how old it is, it might need replaceing.
Before you start looking for causes of where it might be drawing power from, you need to determine that the battery itself is good.
kdf
Depending on how old it is, it might need replaceing.
Before you start looking for causes of where it might be drawing power from, you need to determine that the battery itself is good.
kdf