Battery keeps draining?

2005 CHEVROLET COBALT
120,000 MILES • 2.2L • 4 CYL • 2WD • AUTOMATIC
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DERBYM100
  • MEMBER
  • 1 POST
We have replaced the battery and alternator and it is still draining the battery. It is acting like the battery is drained and acting like i alternator was bad.
Feb 6, 2023 at 5:57 PM
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JACOBANDNICKOLAS
  • ASE Certified Mechanic
  • 110,194 POSTS
  • ASE Certified Mechanic
Hi,

The first thing I suspect is a failed fusible link. A fusible link looks like a traditional wire but functions as a fuse.

On your vehicle, power from the battery-positive terminal goes to the starter. From there, it is jumped to the alternator. Between the starter and alternator is a fusible link. If that has failed, the alternator won't get power and it won't charge the battery.

So, at the alternator, there should be a black wire (according to the attached schematic). That should have battery voltage at all times regardless of the ignition key's position. Check that first and let me know what you find.

Take care,

Joe

See schematic below.
Feb 6, 2023 at 9:43 PM
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