Alternator Not Charging the Battery

Tiny
DEDRICK CONWELL COLLINS IV
  • MEMBER
  • 2008 PONTIAC GRAND PRIX
  • 3.8L
  • V6
  • FWD
  • AUTOMATIC
  • 240,000 MILES
My car wont start unless I give it a boost, I have changed the alternator and the battery. Once it starts by jumping it and I remove the cables, on the dash it says "charging system failure". Can someone please help me with this issue? Some people say its the starter or the voltage regulator. But I am not sure. I need to know exactly so I can get his taking care off ASAP! I am desperate for help!
Tuesday, June 21st, 2016 AT 4:35 AM

2 Replies

Tiny
JDL
  • MECHANIC
  • 16,098 POSTS
Check for applicable trouble codes. To check codes, yourself, at the least you need an obd2 code reader will check manufacturer specific codes as well as po codes, see if anything for charging system. You have regulated voltage control, there are several modes with this system, the voltage output depends on the mode.

You could use a digital multi-meter at generator bat terminal, engine running, with a load turned on, what is the reading?
You can also, check battery amp draw, with everything off. That spec is usually very low, if too high, you have a battery drain. If the battery is down, you need to use a charger to charge it up. It is hard to do any testing with low battery.

If you put the meter leads across battery posts, everything off, the generic spec for a full charge is around 12.6 volts.
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Tuesday, June 21st, 2016 AT 10:01 AM
Tiny
RENEE L
  • ADMIN
  • 1,257 POSTS
Hi Dedrick,

Here is a link to an article that features written step by step instructions and pictures explaining how to do the scan yourself, also I have included a link to our YouTube channel with a how to video on code scanning. Most scanners are inexpensive to purchase, you can purchase one online from sites like Amazon.com. Once you have the codes please get back to us so that we can further assist you. We are always happy to help.

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

https://youtu.be/YV3TRZwer8k

Thank you for visiting 2CarPros.com.

Kindest regards,

Renee
Admin
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Wednesday, June 22nd, 2016 AT 10:49 AM

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