Strange Charging Problem
Thread Starter
Burning Brakes
Joined: Jan 2011
Posts: 818
Likes: 129
From: San Antonio TX
Strange Charging Problem
I recently changed my battery and I have a strange charging issue. I get random low voltage readings on the display that drop below 12 and trigger the "service charging system". I turn off the engine restart and the voltage reads normal between 13.5 and 14. I had Autozone check the battery and altenator and everything is within spec. However, it wasnt acting up when they pulled the voltage.
Any ideas? It sounds like a loose starter wire or grounding issue since I moved the cables changing the battery or a bad battery. I wouldnt think a restart would correct a bad battery charging issue.Car is a 2005.
Any ideas? It sounds like a loose starter wire or grounding issue since I moved the cables changing the battery or a bad battery. I wouldnt think a restart would correct a bad battery charging issue.Car is a 2005.
Safety Car
Joined: Dec 2007
Posts: 4,974
Likes: 148
From: Magnolia Texas
sounds like a cable isn't making contact all the time. once the battery goes bad, it shouldn't "correct" itself like you describe. I'd ensure all cables are tight and making good contact with the battery terminals. just a guess based on what you have told us.
Drifting
Joined: Oct 2007
Posts: 1,565
Likes: 2
From: The Great Pacific Northwest...........I carry a gun cause a cops too heavy.
Also if you want to know what the battery's voltage is I would suggest you check the battery with a meter after the engine has been off for a few hours. The on-board volt gauge is designed to measure the output of the charging system.
Burning Brakes
Joined: Sep 2004
Posts: 1,133
Likes: 20
From: Twisp WA
My first guess would be to pull both battery cables and clean the connections and re-connect and go from there. Since you're having an intermittent problem it sounds like a dirty connection issue some where in the electrical system.
Good luck finding it with the least effort and expense.
George
Good luck finding it with the least effort and expense.
George
Instructor
Joined: Apr 2011
Posts: 204
Likes: 0
From: New York NY
i certainly do not know much about the vette but i do know cars fairly well. Battery should have nothing to do with with a low voltage reading while the car is running. If you remove the battery while the car is running (which i certainly do not recommend), the voltage should still stay stable because the alternator continues to give off more juice than the battery as it spins.
My guess is your alternator (more in depth would be the voltage regulator on the alternator) is faulty. When it cuts out on you for a short time frame, that means that the car is now running off the battery and that being the case, if the voltage does not stabilize back to more than 13+, then the battery and the car will eventually die.
You can have it checked out 1000 times but as long as its giving off 13+ volts, they will never find an issue. Best bet is to replace the alternator ASAP because if it dies out on you, then you'll be stuck in the middle of wherever your at. From what i can see, its not hard to replace at all and costs around 150 dollars from autozone.
Good luck.
My guess is your alternator (more in depth would be the voltage regulator on the alternator) is faulty. When it cuts out on you for a short time frame, that means that the car is now running off the battery and that being the case, if the voltage does not stabilize back to more than 13+, then the battery and the car will eventually die.
You can have it checked out 1000 times but as long as its giving off 13+ volts, they will never find an issue. Best bet is to replace the alternator ASAP because if it dies out on you, then you'll be stuck in the middle of wherever your at. From what i can see, its not hard to replace at all and costs around 150 dollars from autozone.
Good luck.
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Melting Slicks
Joined: Sep 2008
Posts: 2,360
Likes: 59
From: San Jose California
Actually a car will not run these days with the battery dead below approx. 1500 to 2000 rpm's. You can check an alternator by loading the system and checking it's output current and voltage.
You can do a quick voltage drop test to check connections. I would start with a voltage drop test and clean or repair any questionable connections.
Voltage drop example: Put your red lead on the battery (+) positive post itself, then put your black lead on the positive cable. A good connection will show no voltage, it will only show voltage if there is resistance which will cause a voltage drop. If there is voltage clean it and check it again.
Remember when you disconnect your battery that you will need to re-index your windows.
DJ
You can do a quick voltage drop test to check connections. I would start with a voltage drop test and clean or repair any questionable connections.
Voltage drop example: Put your red lead on the battery (+) positive post itself, then put your black lead on the positive cable. A good connection will show no voltage, it will only show voltage if there is resistance which will cause a voltage drop. If there is voltage clean it and check it again.
Remember when you disconnect your battery that you will need to re-index your windows.
DJ
Thread Starter
Burning Brakes
Joined: Jan 2011
Posts: 818
Likes: 129
From: San Antonio TX
Thanks for the tips, I am leaning toward Trueomega and the voltage regulator within the altenator as the culprit. I just purchased the battery and the cables are nice and shiney. The battery terminals are all tight. I will double check the ground and starter wires to make sure they are tight. I will also test the voltage drop.
Burning Brakes
Joined: Oct 2006
Posts: 1,011
Likes: 6
Thanks for the tips, I am leaning toward Trueomega and the voltage regulator within the altenator as the culprit. I just purchased the battery and the cables are nice and shiney. The battery terminals are all tight. I will double check the ground and starter wires to make sure they are tight. I will also test the voltage drop.
Burning Brakes
Joined: May 2007
Posts: 1,171
Likes: 4
From: Columbia Maryland
The battery in my C5 died (because of a loose ground on the battery) and I was able to charge it enough that I could start it. Took it for a drive and got the same voltage fluctuations (11.8v to 15.3v) and a "Service Charging System" messages on the DIC. Thought the alternator was toast, but took it for a long 30 minute drive. After I got home, I turned it off and it started right up and never had anymore issues. I don't think the alternator (or the computer) likes a battery that has had a deep discharge.
Team Owner
Joined: Mar 2008
Posts: 21,502
Likes: 461
From: Southern Utah
Tech Contributor
Joined: Dec 2006
Posts: 10,962
Likes: 29
From: Van Buren Arkansas
Wounded Warrior Escort '11
Most of the electrical distribution happens at the starter solenoid. Also the battery ground cable is right next to it on the engine block. Need to insure all of those are clean and tight and do not forget that it's electrically hot there. Now one other possibility, did you change spark plugs? Yes, I said, spark plugs. If you did and are using E-3's or NGK's, they can cause noise on the electrical system which in turn will cause the PCM to issue incorrect information to the alternator for charging. Yes, its happened to me and many others.
Melting Slicks
Joined: Apr 2010
Posts: 2,790
Likes: 108
From: On the coast North of SF bay
Actually a car will not run these days with the battery dead below approx. 1500 to 2000 rpm's. You can check an alternator by loading the system and checking it's output current and voltage.
You can do a quick voltage drop test to check connections. I would start with a voltage drop test and clean or repair any questionable connections.
Voltage drop example: Put your red lead on the battery (+) positive post itself, then put your black lead on the positive cable. A good connection will show no voltage, it will only show voltage if there is resistance which will cause a voltage drop. If there is voltage clean it and check it again.
Remember when you disconnect your battery that you will need to re-index your windows.
DJ
You can do a quick voltage drop test to check connections. I would start with a voltage drop test and clean or repair any questionable connections.
Voltage drop example: Put your red lead on the battery (+) positive post itself, then put your black lead on the positive cable. A good connection will show no voltage, it will only show voltage if there is resistance which will cause a voltage drop. If there is voltage clean it and check it again.
Remember when you disconnect your battery that you will need to re-index your windows.
DJ
then do the same for the negative cable. You should do this test even if you think the cables are ok because they are shiney. It's a very good test and it can be accomplished with a simple volt meter of most any type.
Team Owner
Joined: Mar 2008
Posts: 21,502
Likes: 461
From: Southern Utah
Most of the electrical distribution happens at the starter solenoid. Also the battery ground cable is right next to it on the engine block. Need to insure all of those are clean and tight and do not forget that it's electrically hot there. Now one other possibility, did you change spark plugs? Yes, I said, spark plugs. If you did and are using E-3's or NGK's, they can cause noise on the electrical system which in turn will cause the PCM to issue incorrect information to the alternator for charging. Yes, its happened to me and many others.
Spark plugs are a known issue