Alternator Voltage Check Please!

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RacerZX
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Alternator Voltage Check Please!

Postby RacerZX » Wed Oct 24, 2012 5:21 pm

My dealer is jerking me around about my alternator going flaky... I measured 13.6V after having trouble starting it, the FSM from my interpretation says 14.1-14.7, and they are now claiming that after tightening the terminals it's reading 13.9 and that is 'within spec'.

Can anybody out there go poke a multi-meter onto their battery terminals with the truck running and see what you find for extra verification please?


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disallow
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Postby disallow » Wed Oct 24, 2012 7:19 pm

The clamps are definitely crap. Just yesterday, my 05 went dead in the walmart parking lot.

I already have a small nail wedged in the negative clamp, now it appears my positive clamp is stretching as well.

I will put my multimeter on it tomorrow.

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mar1
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Postby mar1 » Thu Oct 25, 2012 3:54 am

i havent tested the pathy alternator, but a normal 12V battery charger will give between 13.4 to 13.9V

The charger voltage should never exceed 13.9 volts for long periods
or 14.4 volts for short periods (about 6 hours max).

13.9 is the best "safe" option for chargers.





*edited as per advice below so no one blows their ECU*
Last edited by mar1 on Thu Oct 25, 2012 11:16 pm, edited 1 time in total.

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disallow
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Postby disallow » Thu Oct 25, 2012 7:31 am

I agree with Marwan, anything over 13v is probably OK.

Be careful if you start pulling battery terminals off while the vehicle is running. I had this issue the other night (due to the loose terminals) and accidentally pulled the negative off while it was running. It caused my airbag light to start flashing. I had to do this to fix it:

http://www.thenissanpath.com/viewtopic. ... 538fc51928

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smj999smj
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Postby smj999smj » Thu Oct 25, 2012 10:01 pm

Disconnecting a battery cable on a computer controlled vehicle is never a good idea and could take out the ECM in the process.

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disallow
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Postby disallow » Wed Nov 07, 2012 7:19 pm

Hey Racer,

I finally got around to checking my voltage with my multimeter. Immediately after startup, it measured 14.6v. After 10-15 minutes of idling, it dropped to 14.4v.

That's the same as my old honda always was. Not sure what the spec is on your v8, but I doubt its different than the v6.

Based on that, I'd say you are running a tad low voltage...


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