Mr Phil

I don't know if it is the battery or alternator, but does anybody know why while I'm driving the car the Volt meter will slowly go down even past the middle marker, but when I turn my car back on the next morning the voltage meter will show I have a full charge? I don't know what the deal is but its aggravating me... I mean isn't the battery supposed to charge while driving and not while parked overnight lol

I have already removed the alternator and had it taken down and tested and it tested as good, is there any way to find out if my alternator is not putting out enough amps? Is there a part number reference guide or something that I can check to make sure I have the right alternator installed? I was thinking maybe my alternator is too weak and it's slowly draining the battery because its not putting out enough power, but I don't know how to check if I have the right one or not

NL_SLI_GT

Any other symptoms while driving or is the volt meter the only thing acting up?

Mr Phil

That's the only thing, when I turn the lights on the meter drops a tad, apply brakes it drops again, heater/ac/blinker it drops as well. But like I said once I let it sit over night it, next time I crank it, the meter reads a full charge

Mr Phil

This is usually where it sits while driving until I do anything then it drops right at the 13 marker... a couple times its dropped below 13

Mr Phil

Anyone have any idea what's going on? Or is this just normal for our cars lol

chaman

iTrader: (5)

Mine drops near the yellow area when idling after a good warm up, for example at a stop light.. That is about 11.5. When that happens if you take a voltmeter and measure the output directly from the battery you will see it is around 12.5. Almost a whole volt less. The garage manual I have states that as down as 11.2-11.1 is considered normal. IMO is to low but if the manual says is okay I will just keep an eye out for any further problems.

Mr Phil

well hopefully its all good then... it just sucks though cuz whenever i have to go on a drie longer than like 20 minutes unless its on the freeway the batter drops pretty low imo and i dont wanna get stuck somewhere ya know lol

FormulaColy

i just replaced my alternator and have the somewhat same "problem". when i start the car it reads around 14, then as i drive the car it drops to right above the 13 line, then if i let the car sit and idle it drops down to 13 exactly. But when i park the car and start it up, it is back up to 14 or so.

Mr Phil

did u replace with oem alt? like are u sure its correct output for the motor?

AmDWs6

mine has always been above 13 wouldn't move at all with lights open or not. i am running a optima battery though dunno if that changes anything.

Mr Phil

Well I was planning on buying a new battery but walmart battery was only 550cca and u know the old rule of thumb cubic inches x 1.5 lol

I'm gonna check autozone and a few other places tomorrow

z28bryan

iTrader: (7)

I had this same problem last year. It could be your battery. Something happened in the internals in the battery to prevent it from working correctly. On occasion it would run a tad in the lower voltage area. If your issue is the same as mine, your car battery is slowly dieing. Mine just about died while I was at my local track event last year and I had to limp it home.

I had an optima red and would remove my battery from my car during the winter. I might have let my battery run out once or twice as well and just jump started it to get it going. I believe this is not good for car batteries and keeping them conditioned well. I put my new optima on a battery tender now when not in use.

'99REDTA

iTrader: (1)

Are there any known ground issues with these cars? Had these problems on older vehicles (having the voltmeter mover with accessories turned on and brakes being applied). You can check for ground issues with a set of jumper cables, just attach one end (both or just one if you want) and attach the other end to the body ( preferably Unpainted of course) and see what it does