68 battery gauge ?
Thread Starter
Racer
Joined: May 2009
Posts: 316
Likes: 1
68 battery gauge ?
I have noticed my ammeter gauge that used to display at 0 while driving now runs at +20 and drops to + 10 when idling. voltage regulator?The car starts fine so battery seems to be charging okay. Is this a potential problem with the alternator or voltage regulator?
Drifting
Joined: Mar 2011
Posts: 1,347
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From: Kernersville NC
I have had exactly the same symptoms you describe. How old is the battery? Have Advance Auto, AutoZone, etc check the battery and charging system. I think you will find the battery is weak even though it starts fine. It is not getting fully charged so you see it continually charging. If it is not the battery the check will tell you exactly what the problem is.
Team Owner
Joined: Jan 2006
Posts: 37,637
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From: Crossville TN
I suspect that your battery has enough 'juice' to start the car...but not much more; and I doubt that it will take a full charge. The alternator will TRY to charge a battery based on what voltage it senses in the system. Apparently, the battery won't take enough charge to get the voltage up where the alternator 'believes' that it is charged...so it continues to TRY.
Common symptom of a battery that has 'served its purpose'. Exchange it for a new one from Wal-Mart.
Thread Starter
Racer
Joined: May 2009
Posts: 316
Likes: 1
The battery is only 2 years old bought at walmart.
I suspect that your battery has enough 'juice' to start the car...but not much more; and I doubt that it will take a full charge. The alternator will TRY to charge a battery based on what voltage it senses in the system. Apparently, the battery won't take enough charge to get the voltage up where the alternator 'believes' that it is charged...so it continues to TRY.
Common symptom of a battery that has 'served its purpose'. Exchange it for a new one from Wal-Mart.
I suspect that your battery has enough 'juice' to start the car...but not much more; and I doubt that it will take a full charge. The alternator will TRY to charge a battery based on what voltage it senses in the system. Apparently, the battery won't take enough charge to get the voltage up where the alternator 'believes' that it is charged...so it continues to TRY.
Common symptom of a battery that has 'served its purpose'. Exchange it for a new one from Wal-Mart.
Is my vette stock?? HAHA
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Then you should test the battery and the alternator. Batteries can fail. I had one that seperated internally and would go from full charge to nothing because the post wasnt always connected. Good luck
Instructor
Joined: Feb 2016
Posts: 215
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From: Bismarck North Dakota
take it to the shop, they will be able to check your battery and your alternator, see where the issue is coming from
unless you have one of them really fancy battery chargers that load tests as well as the induction setup for it to test the alternator thats really the only way to be sure.
unless you have one of them really fancy battery chargers that load tests as well as the induction setup for it to test the alternator thats really the only way to be sure.
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Team Owner
Joined: Jan 2006
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From: Crossville TN
Your other possibility is that the main power line from alt to bat or the main grounding wires have deteriorating wire inside (usually near the connectors) or very bad connections. That increased resistance could yield the same results.
[but, my bet is still on the battery]
Have Wal-Mart do a "loaded current draw" test; if the battery checks good, it likely a heavy-gauge wiring problem. An alternator problem is unlikely (but possible), IMO.
[but, my bet is still on the battery]
Have Wal-Mart do a "loaded current draw" test; if the battery checks good, it likely a heavy-gauge wiring problem. An alternator problem is unlikely (but possible), IMO.
Drifting
Joined: Mar 2011
Posts: 1,347
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From: Kernersville NC
Age is no indication of condition and an expensive yellow or red battery is not necessarily better than a moderate priced black one. I had a car that was driven occasionally, like most of us do our Vettes. I had to buy a battery every two years. I had one that I drove every day and had one battery last only two years. A trip to Advance Auto, AutoZone, etc will probably solve your mystery.
Last edited by flyeri; Apr 10, 2017 at 08:21 PM.
Thread Starter
Racer
Joined: May 2009
Posts: 316
Likes: 1
Had my battery and charging system checked. Needed a new battery which I replaced and alternator checked out good. But still running positive on the gauge. Tried replacing the voltage regulator but still the same showing + charge.
Age is no indication of condition and an expensive yellow or red battery is not necessarily better than a moderate priced black one. I had a car that was driven occasionally, like most of us do our Vettes. I had to buy a battery every two years. I had one that I drove every day and had one battery last only two years. A trip to Advance Auto, AutoZone, etc will probably solve your mystery.
Team Owner
Joined: Jan 2006
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From: Crossville TN
The 'sensing' wire going to your alternator doesn't 'know' that the battery is fully charged. You either have a break in that wiring, corrosion on the terminal/connector in the alternator, or similar problem elsewhere in the regular wiring harness (where that line is connected).
OOPS! You have a '68 which has a separate voltage regulator. If you know the regulator to be good, it could be a wiring/connector problem with it. Otherwise, it is a problem in that regulator. You can remove the cover and check/clean the contacts. That may solve your problem.
[Generally speaking, the alternator is trying to crank out excessive current because it is not getting a signal that the line voltage is at 'full charge' condition.]
OOPS! You have a '68 which has a separate voltage regulator. If you know the regulator to be good, it could be a wiring/connector problem with it. Otherwise, it is a problem in that regulator. You can remove the cover and check/clean the contacts. That may solve your problem.
[Generally speaking, the alternator is trying to crank out excessive current because it is not getting a signal that the line voltage is at 'full charge' condition.]
Last edited by 7T1vette; May 4, 2017 at 05:09 PM.
Thread Starter
Racer
Joined: May 2009
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I have opened up the regulator and it looks really good inside.I did get a replacement and tried it out but I got the same results. So I need to look else where for the problem. Not sure how track it down. Guess I'll start by taking another look at the connectors to the regulator. The wires looked okay but maybe I need to look closer at the contacts for corrosion.
The 'sensing' wire going to your alternator doesn't 'know' that the battery is fully charged. You either have a break in that wiring, corrosion on the terminal/connector in the alternator, or similar problem elsewhere in the regular wiring harness (where that line is connected).
OOPS! You have a '68 which has a separate voltage regulator. If you know the regulator to be good, it could be a wiring/connector problem with it. Otherwise, it is a problem in that regulator. You can remove the cover and check/clean the contacts. That may solve your problem.
[Generally speaking, the alternator is trying to crank out excessive current because it is not getting a signal that the line voltage is at 'full charge' condition.]
OOPS! You have a '68 which has a separate voltage regulator. If you know the regulator to be good, it could be a wiring/connector problem with it. Otherwise, it is a problem in that regulator. You can remove the cover and check/clean the contacts. That may solve your problem.
[Generally speaking, the alternator is trying to crank out excessive current because it is not getting a signal that the line voltage is at 'full charge' condition.]
Is my vette stock?? HAHA
Joined: Oct 2015
Posts: 20,145
Likes: 9,278
From: Im not allowed to tell you
2020 C3 of the Year Finalist - Modified
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
your alternator is always outputting and the gauge is showing what the load on the charging system is + or -. No load should have it on the + side. I wouldnt put much stock in the numbers other than a reference. when you turn on the lights does it drop to the - side and even further if you go to the high beams. I would say your meter want working previously and now suddenly is. My meter is always positive until I start turning on electrical components, at night its always in the negative. Been that way for the last year when I fixed the gauges. Runs great no problems
Drifting
Joined: Mar 2011
Posts: 1,347
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From: Kernersville NC
Have you driven it for an hour since you installed the battery? The new battery may need "topping off." If I let mine sit for several weeks without a battery tender it may show +20 or so and take 30 minutes to settle back down to normal. My normal is maybe +5.