951mcomm

My voltage gauge stays at 12 volts and does not fluctuate. Battery is good. Is this normal ?

Lizard944

I don't think they are supposed to fluctuate. If it does I think you may have trouble with the belt being too loose, the regulator, or the gauge itself.

whalebird

A voltmeter reading at the battery will tell the tale

951mcomm

what is it supposed to be at the battery??

Yarf

12.75 vdc for a fully charged new battery with the engine off. With the engine running approximately 13.5 vdc which is the output of the alternator. Does your battery stay charged?

951mcomm

it is not on a trickle charger, but it does get used

whalebird

That would be helpful LOL. Yarf has it right. With the engine off if voltage is less than 12 volts, replace the battery. A completely dead battery creates 12volts, a fully charged battery makes 12.75. If less than 12, you have a dead cell and will not fully charge. There are very rare exceptions that a battery will charge from a dead cell and not suffer damage. Just replace it if it is in question, buy one with a good warranty as auto batteries have a failure rate, when new, above 40%.
Also, you could have an alternator problem. Check the tension on the belt, but if you DO see fluctuations in voltage, the voltage regulator on the back of the alt. is most likely the cause. It's a $45 part, not a $$$$ alternator.

good luck.

951mcomm

the battery does stay charged, it just seemed odd that the volt meter stays at 12 99% of the time.

I will check the voltage at the battery.

choinga

my car usually starts cold with the dash gauge showing correct voltage at around 13.5V...after it warms the gauge drops down to a couple needle widths above 12V even though I know that's not right. I see occasionally blips on my gas gauge and now my temp gauge is doing weird stuff so you may very well have, like I'm presuming that I have, a gauge issue and nothing is wrong at all...

ZW 944

Wow my Battery sucks something auful then... it hovers around 10V when its off, and gets up to just a little over 12 when the car is running..

peanut

either that or your brushes are worn in your alternator maybe ?
Have you tried testing with a multimeter ? the car guages are pretty inaccurate.

bearone

the gage isn't accurate unless it's calibrated/compared to a decent vm by checking voltage at batt or alternator.

when you split the case of the cluster, next to the vm is a small calibration screw to make the adjustment.

87951

Tovrin

I have a similar problem.

when i bought my 944 1 year ago, the alternator would do stay at 12v, i had a problem one day where my stereo cut down and went into safety mode, i checked my stereo wiring and found no problem so i took it to advance auto where they tested my electrical system and said that all was fine until i put a heavy load on the system (i turned on the AC) and the alternator voltage dropped to just under 12v.

i replaced that alternator and for the first week my meter stayed at 14+v, then suddenly it dropped down to 12v again, and now varies between 12 and 14 depending on the weather. the cooler it is outside the higher my needle stays, but since i live in Florida, that's not often.

is that a voltage regulator thing?
I thought it might be a loose wire somewhere or a nut not tightened but i couldn't find a problem, Elliot (drifta944) looked for a bad ground connection for me and couldn't find anything.

i don't take her on long trips now because I'm nervous of getting stranded.

whalebird

Tovrin...your battery is suspect, and all the grounds should be checked and cleaned.

ZW 944

I'm Assuming the alternator is good since the gauge stays level when the car is on, no matter how long. but I never thought about that the gauge could be wrong... would it be as simple as touching each end of a multimeter to each battery terminal to check?

The battery is only one year old, but, walmart brand....