Ground someplace
Thread Starter
Instructor
Joined: Nov 2010
Posts: 127
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From: Twin Falls Id
Ground someplace
so here's the deal, I have an electrical ground somplace draining my bat dead. with the car running the alt reads 15.4 and the bat reads 14.83 with an ohm meter. so this tells me my alt is charging like it should. I have made sure my bat is ground out like it should, everything works when the car is running, lights, radio, seats, mirrors,windows, guages nothing seems to be out of wack.
im stumped.
anyone have any ideas?
new to the vette world.
Marcus
im stumped.
anyone have any ideas?
new to the vette world.
Marcus
Burning Brakes
Joined: Dec 2007
Posts: 889
Likes: 0
Wonder if your hood light switch is always 'closed'? Or maybe another switch is closed and should be open when the car is shutdown and all doors closed. Check your door pin switches and the rest of the pin switches. Just a thought.
Safety Car
Joined: Aug 2001
Posts: 4,883
Likes: 11
From: North Easton Mass
so here's the deal, I have an electrical ground somplace draining my bat dead. with the car running the alt reads 15.4 and the bat reads 14.83 with an ohm meter. so this tells me my alt is charging like it should. I have made sure my bat is ground out like it should, everything works when the car is running, lights, radio, seats, mirrors,windows, guages nothing seems to be out of wack.
im stumped.
anyone have any ideas?
new to the vette world.
Marcus
im stumped.
anyone have any ideas?
new to the vette world.
Marcus
Rick B.
Race Director
Joined: Mar 2006
Posts: 14,112
Likes: 28
From: Florida
so here's the deal, I have an electrical ground somplace draining my bat dead. with the car running the alt reads 15.4 and the bat reads 14.83 with an ohm meter. so this tells me my alt is charging like it should. I have made sure my bat is ground out like it should, everything works when the car is running, lights, radio, seats, mirrors,windows, guages nothing seems to be out of wack.
im stumped.
anyone have any ideas?
new to the vette world.
Marcus
im stumped.
anyone have any ideas?
new to the vette world.
Marcus
It should not be charging more than 14.7 volts at the alt and only briefly over 14.2 volts at the battery, anything more than that is a "gassing charge" and will continue to ruin even new batteries. Fix the alt first.
Charge the battery fully, disconnect the neg term, and test again after a couple days to see if the battery can still hold a charge.
You may also have a drain.
Thread Starter
Instructor
Joined: Nov 2010
Posts: 127
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From: Twin Falls Id
the interior lights I checked the pins out and they do go out with a 10 sec delay on them.
Im thinking it may have something to do with the stereo. it isnt stock alpine deck with a fosgate amp. i noticed that if you hold the cig lighter down for 5 sec with the stereo up to 22 it blows the fuse. so Im gonna take the driver seat out and get into the center consol and c why its hooked up to that fuse.
Thread Starter
Instructor
Joined: Nov 2010
Posts: 127
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From: Twin Falls Id
I assume you meant alt output and battery reading was in volts when charging.
It should not be charging more than 14.7 volts at the alt and only briefly over 14.2 volts at the battery, anything more than that is a "gassing charge" and will continue to ruin even new batteries. Fix the alt first.
Charge the battery fully, disconnect the neg term, and test again after a couple days to see if the battery can still hold a charge.
You may also have a drain.
It should not be charging more than 14.7 volts at the alt and only briefly over 14.2 volts at the battery, anything more than that is a "gassing charge" and will continue to ruin even new batteries. Fix the alt first.
Charge the battery fully, disconnect the neg term, and test again after a couple days to see if the battery can still hold a charge.
You may also have a drain.
As far as I understand why wasnt the ecm programed to handle the car if thats the case.
Last edited by chronos51; Nov 21, 2010 at 08:04 PM.
Thread Starter
Instructor
Joined: Nov 2010
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From: Twin Falls Id
Doing a search of the forum will give you lots of results. This topic comes up all the time. To start, connect an amp meter between one of the battery terminals and cable. You will see a current draw. Remove one fuse at a time from the fuse block until the draw stops. Once you have isolated the circuit causing the problem get a wiring diagram and trace each component in the circuit to find which one is drawing current when it shouldn't be.
Rick B.
Rick B.
Burning Brakes
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From: Native Californian CALIFORNIA
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Melting Slicks
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From: Palatine, Peoples Republic of Illinois
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Has your battery been stone dead? Doing this a few times will ruin a battery and cause all sorts of issues. Definitely check the radio wiring. Sounds like Bubba might have thought he was an electrical engineer.
Thread Starter
Instructor
Joined: Nov 2010
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From: Twin Falls Id
the bat has been replaced 4 times in the last 6 months. maybe its the brand of bat... sears brand
Racer
Joined: Jul 2009
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From: Asheville N.C.
How long is it taking to run the battery down? It could be the clock running, mine does, so I installed a kill lever on the battery so when I'm not driving I'm not draining it. Just an idea, hope you find the problem. 
CF Community Team
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I was chasing a battery drain in my 68 for a while. The alternator charged the car fine when driving so I looked elsewhere. It turned out that the alternator was draining the battery when the car was shut off (bad diode). Pulled the alternator, rebuilt it and the problem was solved.
One other thing to check is the light in the center storage compartment in the rear. Sometimes they don't make a good contact and won't shut off.
One other thing to check is the light in the center storage compartment in the rear. Sometimes they don't make a good contact and won't shut off.
Thread Starter
Instructor
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From: Twin Falls Id
Doing a search of the forum will give you lots of results. This topic comes up all the time. To start, connect an amp meter between one of the battery terminals and cable. You will see a current draw. Remove one fuse at a time from the fuse block until the draw stops. Once you have isolated the circuit causing the problem get a wiring diagram and trace each component in the circuit to find which one is drawing current when it shouldn't be.
Rick B.
Rick B.
Im also checking the bat ground wire to the frame.
Drifting
Joined: Oct 2004
Posts: 1,255
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From: Coralville Iowa
Doing a search of the forum will give you lots of results. This topic comes up all the time. To start, connect an amp meter between one of the battery terminals and cable. You will see a current draw. Remove one fuse at a time from the fuse block until the draw stops. Once you have isolated the circuit causing the problem get a wiring diagram and trace each component in the circuit to find which one is drawing current when it shouldn't be.
Rick B.
Rick B.
Great way to isolate the circuit.
I had a clock that was dead due to the internal wiring being fried. It still had resistance through the windings though. Not enough to blow the fuse, but enough to drain the battery. Disconnected the clock and was I good to go. Found it with the above fuse diagnostics then started checking one connector at a time.
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Thread Starter
Instructor
Joined: Nov 2010
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From: Twin Falls Id
I unplugged the alt and put an ohm meter on the bat. now the bat is pretty dead so the reading was low. I went out a few hrs later and re-took the reading, the reading was the same. so something in the alt is causing the drain. am gonna take the alt to a shop to have it rebuilt.
I have taped up several bear wires on the under carage by the starter as well.
Thread Starter
Instructor
Joined: Nov 2010
Posts: 127
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From: Twin Falls Id
Doing a search of the forum will give you lots of results. This topic comes up all the time. To start, connect an amp meter between one of the battery terminals and cable. You will see a current draw. Remove one fuse at a time from the fuse block until the draw stops. Once you have isolated the circuit causing the problem get a wiring diagram and trace each component in the circuit to find which one is drawing current when it shouldn't be.
Rick B.
Rick B.
Team Owner
Joined: Jan 2006
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From: Crossville TN
I suspect that you just have a bad battery. If the battery won't take a charge, it will always indicate a high charging voltage from the alternator. If the battery was good, after charging a while, the charge voltage would drop to 13v or less. How old is the battery?
Safety Car
Joined: Sep 2007
Posts: 4,451
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From: Indy Indiana
keep in mind that anything going to ground via a short will consume alot of amps and your battery should drain quickly, and it will fry your wires at the ground.
if none of this is true then you have a 'slow drain' thru a resistance of some sort.. perhaps a bulb is on.
your clock, and radio will perhaps pull some drain but only about 10-30 milliamps should be all they are taking and should not drain a good battery for months.
before rebuilding your alt, just take it to autozone and they will check it for free.
a slow drain could also be a dirty top to the battery, allowing current to flow between terminals.
always have the biggest,newest and best battery you can find..
a new battery cures a multitude of sins..
autozone can also check your battery...
if none of this is true then you have a 'slow drain' thru a resistance of some sort.. perhaps a bulb is on.
your clock, and radio will perhaps pull some drain but only about 10-30 milliamps should be all they are taking and should not drain a good battery for months.
before rebuilding your alt, just take it to autozone and they will check it for free.
a slow drain could also be a dirty top to the battery, allowing current to flow between terminals.
always have the biggest,newest and best battery you can find..
a new battery cures a multitude of sins..
autozone can also check your battery...
Last edited by joewill; Dec 10, 2010 at 09:18 AM.
Thread Starter
Instructor
Joined: Nov 2010
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From: Twin Falls Id
the battery is only about 2 months old. after realizing the drain on the battery I put a tender on it and went to put a test light between the bat and neg cable it blew my test light. Im assuming I have a live circut here. I also noticed that the fosgate amp is powering on when I disconect the neg bat cable. the neg on the amp is directly connected to the bat. I am moving the amp ground to another location.