YACT: only reading 13-14 volts on dash

[Lithium381]

Normally i get around 16 or so volts(hard to tell) but as of two days ago i only read 13 volts, and 12 at night when i have the lights on. Randomly it will jump to "normal". This same thing happend last summer, and i(with the help of a friend who worked at an auto repair shop) determined it was the alternator....replaced that and BAM everything went back to normal. Is there a chance the alternator went bad after 9 months? What could other causes be?

 

[Whoozyerdaddy]

I vote alternator again.

Possible Causes:
1. They installed the wrong alternator
2. They installed a bad alternator
3. You have bad karma when it comes to cars
4. Your car's immune system rejected the replacement alternator
5. God hates you

 

[Shawn]

16v seems like a lot. I thought 14.4v was the standard.

 

[Shawn]

Originally posted by: Whoozyerdaddy
I vote alternator again.

Possible Causes:
1. They installed the wrong alternator
2. They installed a bad alternator
3. You have bad karma when it comes to cars
4. Your car's immune system rejected the replacement alternator
5. God hates you

:laugh:

 

[shortspanishguy]

Originally posted by: Shawn
16v seems like a lot. I thought 14.4v was the standard.

14.4 is the standard.

16 doesnt make sense to me.

 

[JasonSix78]

If you're handy with a voltmeter I would take some readings from the battery while it's running. If not, then autozone will do an alternator/battery check for free.

Originally posted by: shortspanishguy

Originally posted by: Shawn
16v seems like a lot. I thought 14.4v was the standard.

14.4 is the standard.

16 doesnt make sense to me.

I was always under that impression too. My GMC truck was reading 15.x volts and I thought it had a bad voltage regulator. I installed a new alternator and battery and it still read the same. I picked up a Haynes manual and found out that voltage is normal.

-Jason

 

[Eli]

Uh, 13-14v is normal. If you were readng 16V and it was really 16V at the battery, you probably boiled all the electrolyte out. Although, dipping to 12 with the accessories on could be seen as abnormal. Is this while idling, or cruising down the highway, or what?

 

[Bassyhead]

The voltage appears near normal. You should specify your vehicle, the alternator rating in amps, and exactly what you had turned on for better answers here.

 

[lightpants]

You need to measure it at the battery with a volt meter, the voltage indicators in the instrument cluster are inaccurate.

 

[Pepsi90919]

you're reading it from the dash gauge. that's why it's wrong.

 

[Specop 007]

I'd be more concerned with 16 volts then I would 12-13.

That said, it could very well be the aalt. I had an alt start flaking out. So I swap it. Now I get no charge.
WTF.
Take the new alt to get it tested, tests good.
I ASS U ME its something else, so drop a couple hundred to have the whole electrical system checked. Tests good.
WTF?!?!
So I take my new alt back to the store. They test it, fails.

Had a flaky alt right out of the box.

 

[arcenite]

16v = Your alternator is on steroids

 

[JulesMaximus]

13-14 is normal. 12 is low though, good luck finding the source of the problem. I had a Mustang GT years ago with underdrive pulleys on it and with the lights on at idle the voltage would drop down to about 12 and the lights would dim...that was because of the pulleys though. It was annoying and I went through batteries about once every 2-3 years because of it.

 

[Lithium381]

Hrm, the gauge is hard to read, i was under the impression that 14v was standard too. Either way it normally rides up high on the gauge, and now it sits on the little line in the middle(12v) or below. It's a 91 Chevy Suburban, accessories are nil, i have an aftermarket headunit on there but i'm pretty sure that's not going to kill the Alt........

 

[Sukhoi]

What should the cigarette plug be reading ('95 Corolla if it matters)? 14.4 volts too? I ask because I just bought a radar detector that includes a voltmeter, and it tells me 12.3V. Is this bad? My battery was giving me troubles starting this past winter when it was well below freezing, but it's been working fine now that the weather is warmer. I'm planning on replacing the battery before next winter anyway.

Oh and while the '95 Corolla is known for having a bad alternator, mine has already been replaced so I'm doubting that is an issue unless a slightly loose belt could be causing the problem.

 

[nboy22]

WTF kind of alternator is that? aren't they supposed to run at 12V from battery when the car is off and then 14.4V when the car is on? Is your alt on steroids?

 

[James3shin]

he got the NAWWWWS on his alternator!

 

[PAB]

You're operating withinn normal parms.

 

[Sukhoi]

Originally posted by: nboy22
WTF kind of alternator is that? aren't they supposed to run at 12V from battery when the car is off and then 14.4V when the car is on? Is your alt on steroids?

That made me think. When I was programming my radar detector I only had the car in accessory mode and not turned on, which may explain the 12.3V reading. I'm going to actually use the thing for the first time today so I'll see what voltage it says once the car is on.

 

[Lithium381]

Well i took it down to a friends shop, and he checked out the system, it read 14.5 while the car was on and 10 when the engine was shut off.......so we replaced the battery on the premise it had a dead cell(it's a 4 year old battery) My friend told me to let it go for a few days and see what happens and let the new battery charge up. I'll update in a few days.

 

[nboy22]

Originally posted by: Lithium381
Well i took it down to a friends shop, and he checked out the system, it read 14.5 while the car was on and 10 when the engine was shut off.......so we replaced the battery on the premise it had a dead cell(it's a 4 year old battery) My friend told me to let it go for a few days and see what happens and let the new battery charge up. I'll update in a few days.

Sounds like a battery problem, 14.5 is pretty good.

 

[duragezic]

Originally posted by: Sukhoi
What should the cigarette plug be reading ('95 Corolla if it matters)? 14.4 volts too? I ask because I just bought a radar detector that includes a voltmeter, and it tells me 12.3V. Is this bad? My battery was giving me troubles starting this past winter when it was well below freezing, but it's been working fine now that the weather is warmer. I'm planning on replacing the battery before next winter anyway.

Oh and while the '95 Corolla is known for having a bad alternator, mine has already been replaced so I'm doubting that is an issue unless a slightly loose belt could be causing the problem.

Cigarette lighter outputs 12 VDC. Figure usually about a +/- 5% tolerance, so you're okay!

 

[cavemanmoron]

Originally posted by: Shawn
16v seems like a lot. I thought 14.4v was the standard.

13.6-14.5v is considered, "normal" range for a working alt.

"12v" Generators, if I recall correctly were 12.6-13.8 normally.

 

[Sukhoi]

Originally posted by: duragezic

Originally posted by: Sukhoi
What should the cigarette plug be reading ('95 Corolla if it matters)? 14.4 volts too? I ask because I just bought a radar detector that includes a voltmeter, and it tells me 12.3V. Is this bad? My battery was giving me troubles starting this past winter when it was well below freezing, but it's been working fine now that the weather is warmer. I'm planning on replacing the battery before next winter anyway.

Oh and while the '95 Corolla is known for having a bad alternator, mine has already been replaced so I'm doubting that is an issue unless a slightly loose belt could be causing the problem.

Cigarette lighter outputs 12 VDC. Figure usually about a +/- 5% tolerance, so you're okay!

Actually I've found out that it only outputs 12V when the car is off. When it's on it has the same ~14V as the rest of the electrical system.

I did 7 hours of interstate driving on Friday and it was rather interesting to see how much the voltage swung around. It was anywhere from 13.4V to 14.2V, and usally hung around 13.7V.

 

[Shawn]

Originally posted by: Sukhoi

Originally posted by: duragezic

Originally posted by: Sukhoi
What should the cigarette plug be reading ('95 Corolla if it matters)? 14.4 volts too? I ask because I just bought a radar detector that includes a voltmeter, and it tells me 12.3V. Is this bad? My battery was giving me troubles starting this past winter when it was well below freezing, but it's been working fine now that the weather is warmer. I'm planning on replacing the battery before next winter anyway.

Oh and while the '95 Corolla is known for having a bad alternator, mine has already been replaced so I'm doubting that is an issue unless a slightly loose belt could be causing the problem.

Cigarette lighter outputs 12 VDC. Figure usually about a +/- 5% tolerance, so you're okay!

Actually I've found out that it only outputs 12V when the car is off. When it's on it has the same ~14V as the rest of the electrical system.

I did 7 hours of interstate driving on Friday and it was rather interesting to see how much the voltage swung around. It was anywhere from 13.4V to 14.2V, and usally hung around 13.7V.

Yeah, the cigarette lighter should be the same voltage as the rest of the car.