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Camry_owner
2003 Camry LE 2.4L
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165 Posts
Discussion Starter #1
My 4 clylinder car alternator voltage running without load puts out 14.4/14.5v but underload when all accessories are on , I get only 12.6 volts.

As far as I know voltage should not drop less athan 13V with all accessories on. But with 2k RPM voltage go over 13v.

Is my alternator volatge faulty? I don't have any issue with chraging the battery. I need expert opinion if anyone knows exactly what is going on.
 

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Registered
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545 Posts
You have to rev it to 2 to check. Basically .5V above battery voltage and your good(batt voltage is 12.6 plus .5 is 13.1 and above). Proper way is to load it with a load tester and measure the amps.

Best!
 

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Camry_owner
2003 Camry LE 2.4L
Joined
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165 Posts
Discussion Starter #4
I have one of those clamp tester that can measure up to 600A DC. But I have seen on youtube one mechanic said when you load all the accessories like AC, heallights, radio etc, the voltage should not drop much even at idle. It should stay close to 13v or above. But my alternator voltage drops to 12.6v which is basically battery voltage on loading all the accessories at idle. Shouldn't it stay close to or avove 13.V even at idle with load?

Alternator voltage is fine at 2k RPM, which is 14.5 but at idle too low with accessories on.
 

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Super Moderator
1995 T100 2WD & 1993 MR2
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6,876 Posts
Your not conducting a true load test which is specific to the battery and done in increments. Your looking for a solution to an undefined problem. If your uncomfortable with what your seeing replace both the alternator with a higher amp unit and get a better battery. You said your battery dropped to 8v, that battery is on it's way out!
 

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Camry_owner
2003 Camry LE 2.4L
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165 Posts
Discussion Starter #6
Battery died after 4 years , had only one year warranty on it. I recently replaced the battery with a brand new battery. My Alternator is 2 years old I guess. How do I do the true load test for my battery ? My batttery CCA is 585. OEM battery was 570 CCA I guess.
 

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Registered
05 camry 07 tacoma
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2,999 Posts
Check for any voltage loss on the positive and negative side of the charging circuit.
What voltage do you have at the alternator compared to the battery post?
Shouldn't be more than a few tenths of a volt.
 

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Camry_owner
2003 Camry LE 2.4L
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165 Posts
Discussion Starter #8
Problem solved: It was my battery doing all kind of things. Before changing battery I had those 12.6 V showing with all accessories on, but after changing the battery alternator voltage does not drop even with all accessores on, stays over 14 volts. Sometimes battery issue can triggger strange engine lights on problem, even though there is no issue with the engine.
 

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9,071 Posts
I’ve had bad batteries cause all the funky stuff such as a charge indicator light on the dash randomly and check engine light for bad o2 sensors. Knew the battery was getting weak until I got stranded one day. New battery fixed that issue.

glad you got your issue resolved
 

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Camry_owner
2003 Camry LE 2.4L
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165 Posts
Discussion Starter #11
I believe with fully functional battery with good charge battery should read at least 12.6 volts without alternator running. While alternator running and all accessories on, a good alternator should give at least above 13 volts. With good battery my alternator volts at battery terminal is now over 14 volts even I am running all accesories.
 

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2004 Toyota Camry, 2017 Toyota Camry, and many many more lol
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667 Posts
I believe with fully functional battery with good charge battery should read at least 12.6 volts without alternator running. While alternator running and all accessories on, a good alternator should give at least above 13 volts. With good battery my alternator volts at battery terminal is now over 14 volts even I am running all accesories.
Both your alternator and battery both run 12.6 normally so working together would be around 14 so you are correct
 
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