Alternator/ Battery

Tiny
PGIBSON6
  • MEMBER
  • 1992 OLDSMOBILE 88
  • 2WD
  • AUTOMATIC
  • 165,000 MILES
I have a 1992 Olds 88 Royale. It died on me in a parking lot a week ago and I have been trying to diagnose the problem ever since. The battery will only charge up to 10.7 V out of the car and then slowly loses voltage. When connected to the car (and the car has been boosted to get it running) the voltage across the posts is at about 13.7 V. It slowly starts dropping down past 12 V (when I stopped measuring). I assume the battery needs to be replaced as it can't hold charge but I can't figure out if my alternator is functioning properly. Is it possible that is malfunctioning alternator could have ruined the battery? I'm only skeptical of accepting the bad battery as the sole cause of my problem because I just bought it 2 months ago. Thoughts?
Wednesday, July 13th, 2011 AT 2:54 AM

3 Replies

Tiny
SATURNTECH9
  • MECHANIC
  • 30,869 POSTS
Lets do this get your battery tested and if its bad get a new one then let me know when you have done that and I will tell you what to check next. Sounds like a bad battery and possible a alternator issue or wiring issue.
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Wednesday, July 13th, 2011 AT 3:21 AM
Tiny
PGIBSON6
  • MEMBER
  • 3 POSTS
I replaced the battery and tested the alternator again. When the car was running I was only getting about 12.9V. Just bought a new alternator and replaced it last night and everything seems to be running smoothly. 12.6V when not running and 14.3V when running. Thanks for your help, perhaps it was just a coincidence that the battery and alternator both crapped out at the same time.
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Friday, July 15th, 2011 AT 1:37 PM
Tiny
SATURNTECH9
  • MECHANIC
  • 30,869 POSTS
Your welcome its not uncommon for a weak battery to take out a weak alternator or the other way around glad to hear you got it all fixed.
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Friday, July 15th, 2011 AT 4:16 PM

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