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Alternator Experts needed

Printed From: the12volt.com
Forum Name: General Discussion
Forum Discription: General Mobile Electronics Questions and Answers
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=63747
Printed Date: April 30, 2024 at 5:31 AM


Topic: Alternator Experts needed

Posted By: nyc951
Subject: Alternator Experts needed
Date Posted: October 03, 2005 at 9:48 PM

Hi:

When starting my car in the morning, the alternator does not immediately begin charging the battery.  It doesn't provide any output (as indicated on my dash gauge) until either of two things happen:

- I rev the engine a  few times to bring up the RPMs
- I let the engine idle for about 5 minutes

Then the alternator starts working fine, for hours at a time, until I stop the engine and park it for the night.  The whole cycle begins again in the morning.

The bearings are fine and the voltage regulator is relatively new.  It's an adjustable type and was set at the max setting, which is about 14.4 Volts.

Can anyone tell me why the althernator needs a "warm up" period?  Thanks in advance.




Replies:

Posted By: skoldspuppy
Date Posted: October 04, 2005 at 6:45 PM

Most Alternators are never on all the time, most kick on at around 1000-15000 rpms to start charging the battery
If Alts were charging all the time, they would wear out very quickly as in the case of my former HO for my Civic, it died after 6 months cause it was active at 500rpm my idle speed is 850rpm

Just a thought, im sure more people will comment on this soon

--Skold



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2004 Honda Civic Ex 4Dr

Kenwood DDX-7015/W Nav
4 Fosgate T152C
Hifonics Brutus BX1500D
RE XXX 12 in a 4 Cube Snail Shell




Posted By: sedate
Date Posted: October 06, 2005 at 12:04 AM
skoldspuppy wrote:

Most Alternators are never on all the time


Huh? Whenever your car is running a belt would be turning the alternator... so it would be 'on' so to speak. Perhaps the alternator doesn't reach 14v until a certain RPM, but the mechanical action of a magnet moving around another *will* produce a current. It .. ya know.. has to.

Rewound alternators frequently burn up quickly.. not the result of being 'on' all the time, but the result of massive power loads and strain on the voltage regulator... all that heat really takes it to 'em when you start cramming 200-amps of output in a OEM case made for 90.

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"I'm finished!" - Daniel Plainview




Posted By: supradude
Date Posted: October 06, 2005 at 4:40 PM
I have found the opposite of nyc951. I have noticed on the cars I have owned when I first crank it the alternator will show charging MORE for a while, then after it runs it will slowly (the gauge hand) will start to lower. Cranking will take some charge from the battery and the alternator will charge it back to normal, so to speak. It sounds to me as if the voltage regulator may be the problem: then again I'm no expert on this. 

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'85 Toy




Posted By: skoldspuppy
Date Posted: October 06, 2005 at 7:16 PM

sedate wrote:

skoldspuppy wrote:

Most Alternators are never on all the time
.


Im meant charging all the time

--Skold



-------------
2004 Honda Civic Ex 4Dr

Kenwood DDX-7015/W Nav
4 Fosgate T152C
Hifonics Brutus BX1500D
RE XXX 12 in a 4 Cube Snail Shell




Posted By: fingaz22
Date Posted: October 06, 2005 at 8:24 PM
it might be just the gauge that takes time to show voltage if you want to be sure get a volt meter and put it to your battery when the problem is happening and that way you'll eliminate the gauge and the wiring to the gauge. i've seen fords do this with both oil pressure and voltage. so check and make sure the gauge is working right by seeing what voltage is at the battery or directly from the alternator if accessable.

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JUST ONE MORE AMP!!!
hu,alpine cva 1005/dva 5205
sound processor,symmetry(first one).
sub amp,power 1000 the terminator.(1992).
subs,spl comp dual 1 ohms.
punch 150hd on a 10" ev.
alotofhighs





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