Voltage around 12.9...normal?
#1
Voltage around 12.9...normal?
For a while now my voltage has been on average around 12.9.
When the engine is cool like when I first start the car in the morning it is at 14.0-14.3.
A little later when the engine is nice and warm, the voltage will be between 12.5-13.5. Mostly between 12.5-13.0
*Reving the engine hardly makes any difference. It will probably go up 0.2 volts or nothing.
*I don't see any symptoms like headlights dimming.
*Battery is brand new. Tried 2 other batteries as well, same thing.
*Wires are all new. Both the + and - leads.
I'm checking the voltage both thru the instrument panel and a multimeter.
Now my question is...is this normal on a GTO or is my alternator failing...or is there some other problem?
When the engine is cool like when I first start the car in the morning it is at 14.0-14.3.
A little later when the engine is nice and warm, the voltage will be between 12.5-13.5. Mostly between 12.5-13.0
*Reving the engine hardly makes any difference. It will probably go up 0.2 volts or nothing.
*I don't see any symptoms like headlights dimming.
*Battery is brand new. Tried 2 other batteries as well, same thing.
*Wires are all new. Both the + and - leads.
I'm checking the voltage both thru the instrument panel and a multimeter.
Now my question is...is this normal on a GTO or is my alternator failing...or is there some other problem?
#2
On The Tree
Sounds like your alternator is weak. While checking voltage with a good meter, car warmed up and idling, turn on every accessory. If voltage drops into the 10-11 volt range you need an alternator. If voltage goes up or stays the same you're kinda ok. Your voltage is low compared to other cars, I've never tested a GTO charging system before. Good luck
#4
Ok folks! Just changed my alternator with another one from the junk yard, which looked pretty new, but the exact same thing is happening!
Any idea what's going on?
Any idea what's going on?
Last edited by Freefallin; 05-24-2014 at 12:02 PM.
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#8
Haha! That's a joke! Around here, junk yard parts are more "as is". They do give you a guarantee thou...if it turns out to be defective, the hassle of installing and uninstalling is on you.
#9
UPDATE: The voltage is dropping when the fans come on.
When they are not working, the voltage stays steady at 14.0-13.9.
Aside from the alternator, wires/connection and battery, what could be causing this?
When they are not working, the voltage stays steady at 14.0-13.9.
Aside from the alternator, wires/connection and battery, what could be causing this?
#13
I had the same problem.
The alternator is not the problem. The battery cables are the issue. The cables are not thick enough to conduct the amount of electricity needed to feed the fans, accessories, AC, ect...
And as our cars get older the conductivity of our battery cables diminshes due to rust and deterioration.
The solution is to run an extra cable from the alternator to the battery and also add an extra grounding. It will improve the efficiency of the charging system.
On my car I run HIDs, Interior LEDs, Gauges, Headunit, upgraded sound system, back up cameras. All this with a 25% underdrive pulley and headers in the miami heat. My voltage now never drops below 13.4. After i did the extra cable and ground
The alternator is not the problem. The battery cables are the issue. The cables are not thick enough to conduct the amount of electricity needed to feed the fans, accessories, AC, ect...
And as our cars get older the conductivity of our battery cables diminshes due to rust and deterioration.
The solution is to run an extra cable from the alternator to the battery and also add an extra grounding. It will improve the efficiency of the charging system.
On my car I run HIDs, Interior LEDs, Gauges, Headunit, upgraded sound system, back up cameras. All this with a 25% underdrive pulley and headers in the miami heat. My voltage now never drops below 13.4. After i did the extra cable and ground
#14
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It's normal for voltage to be high after starting as the battery is more discharged and the alternator puts out a higher voltage to charge it. After it replenishes it only needs a little above 12v to "trickle" charge it. I think mine is around 13V after it "recharges".