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Discussion Starter · #1 ·
those of you with voltmeters

Ok, so I was sitting in the drive through of Taco Bell and I noticed my voltage was right at about 12V. In the past when idling it was at about 14V. While I'm driving the voltage goes back up to about 13.7V. Is it supposed to be at 12V while idling, or is my alternator going bad?
 

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RE:those of you with voltmeters

Did you have your AC or defroster on? I noticed that when my car had the AC on the voltage would drop, also when the rear defrost was on, its drops alot.
 
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RE: those of you with voltmeters

Yea, the more accesories you have on, the lower the voltage will go. And some accesories have a bigger pull on the alternator than others. Check to see what the voltage is with the car at idle with no accesories on. It should be mid 13's to low 14's. If it's still reading around 12 volts, then your alternator may be on its way out. But as long as it doesn't drop below 12 volts, you should be okay.
 

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RE: those of you with voltmeters

IIRC from my Factory Service manuals,
Voltage output from the altenator can vary from 10-15amps, without setting off a dtc
 

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RE: those of you with voltmeters

Mine are at 12 to 13 on any given day. 1 digital reads 14 sometimes, while the other non digital reads about 11 to 12. I have 3 different meters, 1 in dash, and 2 in the trunk. I like watching the needles jump during those amp stressing bass notes.
 

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RE:those of you with voltmeters

Mine is run to the ignition wire. Runs 14.2 at all times, unless lights and system are on, then around 13.7 -- has NEVER dipped below 12.7, even at peak times.

I have the stock alternator and a yellow top, with a Batcap 300 in the trunk.
 

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Discussion Starter · #7 ·
RE:those of you with voltmeters

It was runnin 14V tonight with the heat, radio, and headlights on. It could maybe go down when the car is warm?? :shrug: I dunno, I have a "lifetime" waranty on the alternator so maybe I'll get a new one soon.
 

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RE: those of you with voltmeters

Well if your car is off, you'll get ~12v(11.7) you are only running off the battery, and that 11.7 is
reading the battery, you could maybe lose .3volts in the wiring maybe? nothing to worry about there
I don't think
 

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RE: those of you with voltmeters

No worries but to drain the battery when its off. But thats about normal to be slightly under 12v.
 
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RE:those of you with voltmeters

With my system turned to the max , my gauge bounces back between 12 and 14 volts :biggrin: It beats with the music :)
 

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Discussion Starter · #12 ·
RE:those of you with voltmeters

I'm driving home from classes today and I notice my batt light is on....I look at the voltmeter, damn it's at about 11.7 volts....I turn off the radio which was the only thing that was on and no luck, still 11.7 volts. Even at high/low rpm it stayed the same. I drove a little more then re-start the car. The voltage jumps back up to about 14 where it should be.....WTF? You think the alternator is going out? It's only 10k miles old.
 
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Check your battery terminals and all your ground connections. I had a bad connection on my terminal and my volts dropped down that much while driving
 

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Discussion Starter · #14 ·
just checked them and they are clean as a whistle.....I think I may have to wait 4 hours for pep boys to change it again
 
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