Low voltage+New batt+refurbed Alt.=??

red95r · Jul 3, 2011

Well to start off with I bought the car with a rather old battery. It starts up every time though. It also has a refurbed Alt. from the looks of it.

Now I replaced the battery, because upon start-up the voltage meter would be straight up and down, and the hotter it got the lower the gauge would read and sometimes flicker. The battery was also 3 yr old/440cca.

I purchased a new 800cca optima battery, put it in and now with just inside air on and the occasional radiator fan on, the voltage sits really low. Even lower if at idle with me holding the brake.

All of this has me concerned. So that said where does everyone else's voltage meter sit? Again I know these gauges aren't all that accurate. Do you think I should test the Alt.? if so how?

Thoughts? Ideas?

Willis_98GT · Jul 3, 2011

My car does this too.. sad day sometimes

red95r · Jul 3, 2011

so this is normal for our cars?

theory29zane · Jul 4, 2011

mine does it too. when its cooler in the morning i dont run the ac on the way to work its up a bit then in the after noon thanks to the tx heat i have it on full blast its down a bit but i have never had a starting problem or it killing out so i figured it was normal.

lutter94 · Jul 4, 2011

My voltage gauge has always been normal.....The alternator did go out last year, it was pretty obvious when it happened (voltage dropped like a rock), replaced it and it works fine. I would be tempted to get a new alternator. Just because it looks like a reman doesn't mean it works right.

red95r · Jul 4, 2011

Yeah at first when the voltage drops due to headlights or anything intensive itll pick right back up to where it was. as it gets hotter it wont charge back up it just becomes a drag.

red95r · Jul 5, 2011

Did a voltage check. At first when I connected the leads to the battery it read 12.45V. This is on a new optima battery.

Car running reads 14.4-5. With a load of headlights/fogs and blower it still sits at 14.5, but within a minute and a half it drops to 14.1X.

This is a sign of a weak alt? The car was cold, and usually it'll read lower on the interior gauge once its hot.

Venomous96Cobra · Jul 5, 2011

are you checking your reading from the battery or directly from the alternator?

red95r · Jul 6, 2011

from the battery.

lutter94 · Jul 6, 2011

Sounds like your gauge is just strange then. I would think you should be safe with 14 volts.....Have you tried comparing your dash gauge to your voltmeter?