Battery or ALT

SilverLS

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Im almost positive its the battery ....but I will ask you guys any ways.....I am sitting in the car (WORKING) and Iam watching the battery gauge right now its right above 12 but below 13 I have nothing onbut the car and radio>>>NO Light Air Power Inverter ect......I have a SMALL SMALL amp that draws no power But even when I turn off still no change......If I give it a little gas It raises the volts to about 14......Is the alt starting to go .....I understand the alt keeps the car running and charges the battery.....I need to stop a discount on the way home......
Anyone wanna give some feedback....
 
SilverLS said:
Im almost positive its the battery ....but I will ask you guys any ways.....I am sitting in the car (WORKING) and Iam watching the battery gauge right now its right above 12 but below 13 I have nothing onbut the car and radio>>>NO Light Air Power Inverter ect......I have a SMALL SMALL amp that draws no power But even when I turn off still no change......If I give it a little gas It raises the volts to about 14......Is the alt starting to go .....I understand the alt keeps the car running and charges the battery.....I need to stop a discount on the way home......
Anyone wanna give some feedback....

Could be voltage regulator or low idle RPM. At what RPM does the voltage kick up to 14?
 
as soon as you give it any gas.....I just changed the spark plugs last night and I seems like the car is idleing smoother and mabye lower it idles at 800RMP (I only chaged driver side last night )
 
SilverLS said:
as soon as you give it any gas.....I just changed the spark plugs last night and I seems like the car is idleing smoother and mabye lower it idles at 800RMP (I only chaged driver side last night )

I would start with the voltage reg or alternator after having the Battery checked. If you have higher miles it is probably the regulator getting weak. I have not had to replace one on the LS, so I don't know their longevity. Usually it is solid state on the back of the alternator. I don't know what your idle is supposed to be, but it still could be low idle. Low idle speed and weak regulator display the same low voltage as you indicate.
 
Yeah I am almost done with this case Then Im on my way to discount .....I hope its just the battery(warranty) anyone know how much and how hard it is to do the voltage regulator......55050 miles on the car as of 11:27 am
 
Normal behavior.

Most alternators are designed to not have any or very low output at idle speeds. If your gage is sitting at 12-13 volts at idle, that is normal behavior. As soon as you gas it, the voltage climbs because the draw also climbs. If you get flicker at idle, it may be that the battery is not maintaining peak. It is the function of the alternator and internal regulator to keep the battery at peak. If the system has a lot of high draw components, the constant cycle will eventually cause issues with the batteries ability to hold full charge. Also underdrive pully's also can cause the alternator to not keep the battery at peak because the idle speed of the alternator is lower than stock. Most alternators only go into charge mode at RPM levels above 1500-1600 RPM's. Hope this helps.
 
bufordtpisser said:
Most alternators are designed to not have any or very low output at idle speeds. If your gage is sitting at 12-13 volts at idle, that is normal behavior. As soon as you gas it, the voltage climbs because the draw also climbs. If you get flicker at idle, it may be that the battery is not maintaining peak. It is the function of the alternator and internal regulator to keep the battery at peak. If the system has a lot of high draw components, the constant cycle will eventually cause issues with the batteries ability to hold full charge. Also underdrive pully's also can cause the alternator to not keep the battery at peak because the idle speed of the alternator is lower than stock. Most alternators only go into charge mode at RPM levels above 1500-1600 RPM's. Hope this helps.

Well said!!!
 
Thanks

I used to in a former life be a senior service technician for a very large and well respected motor repair shop. I worked in all of their divisions from large commercial to automotive. I liked the automotive part of it best. I have worked on everything from fractional horsepower motors to huge mega kilowatt generators at nucular plants. I am always happy to help with electrical issues. This site rocks, and knowledge is not knowledge unless you share it.
 
ok but this is something new for my car....When I am sitting in the car all day I watch the gauge and it normally stays around 13.5 14 when I sitting there......The guy at discount says the battery it good .....I was sitting there at 2,000 rpm's and it was only about 13.3 or so volts.....How hard is the alt.job if its not to bad I will take it out and go have it tested outside of the car....I looked under the hood and it is on the bottom THANKGOD it looks like it should be fairly simple....I know how to work on cars ( been doing it for some time) so I know I can do it just wondering how hard (indepth) it is.....
 
Why remove the alternator....

The alternator can be tested just a s well in the car as it can out of the car. Actually it is better to test on the car, so that it can be tested under actual conditions. If the battery is tested good, then the alternator is doing its job by keeping it charged. If the movement of the needle is the only thing that concerns you, it may be caused by the age of the alternator, the condition of the grounds, different temperature related resistance values of wiring, or any number of things. I would have the alternator/battery/charging system tested in its in car state by a reputable battery/alternator/electrical shop and let them make a recommendation. I personally run the best battery/alternator combination that I can afford on all of my vehicles. I usually run Optima Yellow Top Deep Cycle batteries, and Motorcraft Alternators that I take to a local Alternator shop and have rebuilt to High Output Police Package Specifications. My reasons for using a deep cycle battery are direct from an Optima site.

1. Delivers higher peak amps faster than conventional batteries
2. Provides up to twice the life of conventional batteries
3. More consistent voltage across the discharge curve
4. Superior cold and hot weather performance vs. conventional batteries
5. Available in models with SAE posts, stainless threaded studs, or both
6. Spill-proof, even if the case is physically ruptured
7. Will not off-gas in normal operation, eliminating fumes, odor & corrosion
8. Over 14x more shock and vibration resistant than conventional batteries
9. Provides more power from a smaller package
10.True zero maintenance
11.Holds charge better during periods of nonuse
12.Operates in any position without spilling
 
I agree I have an optima and the guy tested it and it said battery good......Now I just had to run to the office about 5 miles one way and when Im on the gas it is on 14 volts on when Im sitting at a light (with air and light on or air and lights off) it drops to 12.....Could it be a pully idler going back or even the belt.....I believe the belt to have 55079 miles on it......I think I gonna try the belt first.....
 
I cant seem to find the belt routing diagram....Not under the hood or in the engine bay at all??? I searched in the online book but only got seat belts
I know someone got it....Looks like its gonna be a pain without removing intake and all the other goodies up top huh???? If someone could point out to me the diagram it would be great...
 
noone has a belt diagram......
I went to discount and they told me the battery is fine
I went for a night drive and had the headlights and fog lights on.....when sitting at a light it dropps to 12 and after a few minutes the battery light flashes......if I give it gas it goes up a little but if I give it full throttle it read 14 solid until I stop again......I guess I need a 200.00 altenator......
 
reading from post 1 you need a new alternator. In most cases You should see MINIMUM mid 13's even at idle...and 14+ anything but.
 

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