Question about 2002 GMC Sierra 1500

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Truck keeps dying, dont know what else to do?

My truck battery will die overnight, i unhooked my negative post and connected a multimeter to the battery and to the negative cable i just unhooked, the voltage was like 12.6V is this normal, what does this mean. After doing this i went to my my amp and unhooked it completely from the battery, i then used the multimeter to test the amp and t was drawing like 8.8V when it was completely disconnected? is this normal? is this what is draining my battery? anyways i pulled all the fuses on my amp so it was drawing no volts and put the charger on the battery overnight. wake up in the morning and it barley turned over after charging it for 9 hours. could this be because my battery has been drained and charged like 20 times and may be burnt out? please enlighten

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A bit confusing about where the amp comes into this but when you unplug your amplifier there will be power still stored in it for awhile until it disapates. You will notice this if you leave your meter on it and watch it go down. Now, the only reason the amp would cause problems is if, when you are running your vehicle, the amp is drawing more juice than your truck is able to keep up with. With this scenario the amp is causing the problems. If your battery is not taking a charge after 9 hours than you do need a new battery and you have to correct the over draw from your amplifier. My suggestion is to take the amp out of the loop, buy a new battery and do some more research on proper audio design.

Posted on Jan 24, 2013

  • johnny rebel
    johnny rebel Jul 13, 2014

    get a new battery,but,first take your battery to autozone and have them check it,buy a new battery at walmart,save your receipt in a cool olace and copy to a computer,print it out and tape it into a bag and keep near battery,{the heat will ruin original receipt},take the battery back and exchange it every 2 or 3 years and you will always have a good battery,also,put a disconnect on your amp,do not run power through ignition switch,the draw will kill the switch,dont leave the amp on unless you are running the car,also get capacitors for your amp,they store power for the bass boost,you need a huge alternator i believe.


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12.6VDC is a good output from a vehicle battery. The measurement of 8.8Volts is not drawing anything, it is Voltage not can draw current in Amps or Watts only. Check the Amperage draw of your Amplifier to see what it draws and compare that number to the number of Amp Hours written on the battery. Yes, it may be what is draining the battery, like leaving your headlights on overnight! Do the math! Drawing the battery down to a very low Amperage could damage the cells in it, that's why golf carts use what is known as Low Dwell batteries that can discharge way down without damage. Have it tested or test it yourself with a relative gravity tester available at your local auto parts store. Read the instructions will tell you how bad the battery is damaged and if you need a new one. Have fun learning stuff like I do...

Posted on Jan 24, 2013


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Posted on Jan 02, 2017

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SOURCE: Won't start after battery died and recharged

Sounds like low voltage.
Get a boost from another car with a good set of cables.
Once started check voltage with booster car disconnected.
Is it around 14 volts?
If so,the truck is charging, so it may be time for a new battery.

If the voltage is at 12 or lower while running the truck is not charging.
May be time for a new alternator.

The battery should have charged enough in 1 hour to start the truck.
You may need a battery and alternator.

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check the batt and alt

Posted on Jan 18, 2010

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SOURCE: Truck Battery Keeps Draining?

Well the fuse itself is not the issue, but there could be a solenoid or other electrical component draining the battery. And also cause the light to be on.
I would have the body computer scanned for trouble codes to find out why the service light is on. There should be trouble codes just like when the check engine light is on.
You could probably pull the fuse and run it in 2wd also.

Posted on Jan 19, 2013

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