Alternator

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83kid

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Hi,
I have an 83 k10 with a 350 in it
when its running, it overcharges a little bit, getting just below 15 volts on the battery posts when running
So, i replaced the battery and battery cables: didn't fix it
Had a mechanic looks at it, said it was either the battery or the alternators voltage regulator was broken, so im buying an new alternator.
How do i know which one to get?
http://www.napaonline.com/Catalog/R...k=Keyword&Nty=1&N=599001+101983+50014+2014036

Should i get 37-42 amp, 56-66 amp, 78 amp, or what?
Not running anything heavy duty electrical wise, but if its just a matter of how much i want, what would be best?


Thanks!
 

MadOgre

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Woooo!!!

14.75 volts its absolutely perfect for an alternator's out put. 14.25-14.75volts is well with in normal parameters.

Why are you changing the alternator?

The best replacement is the 108amp unit. you can still find reman ones at the parts store. You may have to undo the 4 body housing screw bolts and rotate the 2 halfs to line up with the old bracket set up. No biggy though.

Just for reference my 108 amp alternator produces 14.25 volts when running at the battery.
 

chengny

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2X MO's advice.

Unless you are constantly having to add water to your battery, I wouldn't bother replacing the alternator. You might be a little on the high end, but normal charging voltage for any 12 volt battery is at least 14.5 at idle. The GM spec for voltage regulator range is actually 12.5 - 15.4
 

83kid

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Oh ok, cause i replaced my starter and the voltage jumped up quite a bit, and i assumed it was the voltage regulator in the alternator, as the mechanic caid it was just under 15 volts and anything more than what it is at then ishould replace it, so ill just leave it for now


Thanks!
 

350runner

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Did you ever change those battery cables?

Sent from the dust in front of you!
 

83kid

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Yup, both, did absolutely nothing, bought a new battery too, but it had an older one in it anyways
 

MadOgre

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The voltage jumped up cause when you changed the starter you inadvertently cleaned the connections at the starter which is where the battery connects to the alternator and the rest of your trucks power supply. Its like a junction box, everything meets up at the starter.

When you took all the cables off and replaced the starter you freshened up all the connections by removing and reinstalling them.
 

MadOgre

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I would change that mechanic though as he is definitely a moron!
 

firebane

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The voltage jumped up cause when you changed the starter you inadvertently cleaned the connections at the starter which is where the battery connects to the alternator and the rest of your trucks power supply. Its like a junction box, everything meets up at the starter.

When you took all the cables off and replaced the starter you freshened up all the connections by removing and reinstalling them.

Just to further add to what has been said already the way our trucks get wired and a lot of other vehicles for that matter is this.

One large cable goes from battery to the starter. From the starter a second wire runs from it to the junction block on the firewall. From there power is provided to the truck.

If anything along those routes are dirty or corroded power to the entire truck is going to suffer.
 

350runner

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I would change that mechanic though as he is definitely a moron!
Ah... Now I remember I think there was a thread where it was agreed that this voltage reading you are getting was good. Why start a new thread? X2 on the mechanic.

Sent from the dust in front of you!
 

Lastwords

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When I rev my motor up the volts go with it. Close to 18 volts. Fried my damn stereo. That is when you know the alt has to go.
 

79K10

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For sure!, 18 volts? Damn that's high lol


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