Alternator Help - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Ikera · 10-25-2013, 01:25 AM

my volts are low,
ignition off ~11.0V
idling ~11.0V
@2000RPM ~12.0V

so the alternator is generating some electricity, just not enough to keep the battery charged

the FSM alternator trouble shooting didn't apply to me

Ignition of - Batt light on (normal)
idling - Batt light off (normal)
@1500RPM - Batt light off (normal)

checked the fuses under the hood, everything is ok
the voltage reading under the hood, in the truck and at ECU is all the same

the engine is KA24ET, there was no water leaking on the alternator, but I do have a hard hitting 12" Sub and an AMP in the hatch

HELP!!

rwtf · 10-25-2013, 01:49 AM

um....bad alt? volt regulator? lol pretty damn obvious

Ikera · 10-25-2013, 02:48 AM

why doesn't the batt light come on in any of the trouble shooting scenarios?

alternators aren't cheap wouldn't want to replace if I don't have to.
If there is nothing else to try with an alt in the car I'll take it out and take it apart then and check the voltage regulator

rwtf · 10-25-2013, 02:57 AM

you know advance can test them...for free right...? facepalm.

Ikera · 10-25-2013, 10:19 AM

nope, and I didn't know what "advance" is until I googled it. The nearest one is across the border, but I will try to find out if anybody else does this type of service around here

ultimateirving · 10-25-2013, 11:06 AM

Quote:

Originally Posted by Ikera

nope, and I didn't know what "advance" is until I googled it. The nearest one is across the border, but I will try to find out if anybody else does this type of service around here

What does can have for automotive parts stores? Auto zone oreilly can both test em here stateside

drumer_boy456 · 10-25-2013, 11:12 AM

blkvrtswp · 10-25-2013, 11:27 AM

Lots of stores are no longer testing alternators due to the newer complex electronic ones giving constant 'bad' indications. Great for sales until the customer catches on. I actually had a hard time finding anyone other than Autozone here in NY.

You can find rebuilt alts on ebay - look for good feedback, last one I bought was around $75 shipped and it was excellent.

***FaLKoN240*** · 10-25-2013, 11:32 AM

How old is the battery?

What's your battery's resting voltage?

What is the battery's voltage reading when running? When you rev it does the voltage go up?

If the battery is below 12 volts with the car off, the battery is probably on it's way out.

If you're running anything below 12V when the car is running the alternator is not returning enough voltage to your battery and is actually shortening the life of your battery.

Ikera · 10-25-2013, 11:59 AM

Quote:

Originally Posted by ultimateirving

What does can have for automotive parts stores? Auto zone oreilly can both test em here stateside

Lordco and NAPA

Quote:

Originally Posted by FaLKoN240

How old is the battery?

What's your battery's resting voltage?

What is the battery's voltage reading when running? When you rev it does the voltage go up?

If the battery is below 12 volts with the car off, the battery is probably on it's way out.

If you're running anything below 12V when the car is running the alternator is not returning enough voltage to your battery and is actually shortening the life of your battery.

resting about ~11.0V, idling same ~11.0V if I rev it up to 2000PRM the voltage does go up to ~12.0V

I'll try swapping in a battery from my other car

shogunstyles15 · 10-25-2013, 01:10 PM

Did you have any luck finding an auto parts store to test your alt in your area? You can go around in circles trying to trouble shoot it but the EASY way is to take the part out and take it to the store. Other than that you already have all the info you need. Its operating below acceptable levels so its time for a replacement. GL with your project.

10-25-2013, 01:25 AM	#1
Ikera Join Date: Jul 2009 Location: Vancouver Age: 39 Posts: 41 Trader Rating: (0) Feedback Score: 0 reviews	Alternator Help my volts are low, ignition off ~11.0V idling ~11.0V @2000RPM ~12.0V so the alternator is generating some electricity, just not enough to keep the battery charged the FSM alternator trouble shooting didn't apply to me Ignition of - Batt light on (normal) idling - Batt light off (normal) @1500RPM - Batt light off (normal) checked the fuses under the hood, everything is ok the voltage reading under the hood, in the truck and at ECU is all the same the engine is KA24ET, there was no water leaking on the alternator, but I do have a hard hitting 12" Sub and an AMP in the hatch HELP!! __________________

10-25-2013, 01:49 AM	#2
rwtf Zilvia Addict Join Date: Jun 2011 Location: Maryville, TN Age: 33 Posts: 830 Trader Rating: (3) Feedback Score: 3 reviews	um....bad alt? volt regulator? lol pretty damn obvious __________________

10-25-2013, 02:48 AM	#3
Ikera Join Date: Jul 2009 Location: Vancouver Age: 39 Posts: 41 Trader Rating: (0) Feedback Score: 0 reviews	why doesn't the batt light come on in any of the trouble shooting scenarios? alternators aren't cheap wouldn't want to replace if I don't have to. If there is nothing else to try with an alt in the car I'll take it out and take it apart then and check the voltage regulator __________________

10-25-2013, 02:57 AM	#4
rwtf Zilvia Addict Join Date: Jun 2011 Location: Maryville, TN Age: 33 Posts: 830 Trader Rating: (3) Feedback Score: 3 reviews	you know advance can test them...for free right...? facepalm. __________________

10-25-2013, 10:19 AM	#5
Ikera Join Date: Jul 2009 Location: Vancouver Age: 39 Posts: 41 Trader Rating: (0) Feedback Score: 0 reviews	nope, and I didn't know what "advance" is until I googled it. The nearest one is across the border, but I will try to find out if anybody else does this type of service around here __________________

10-25-2013, 11:12 AM	#7
drumer_boy456 Zilvia Member Join Date: Dec 2011 Location: topeka, ks Age: 34 Posts: 161 Trader Rating: (4) Feedback Score: 4 reviews

10-25-2013, 11:27 AM	#8
blkvrtswp Zilvia Addict Join Date: Oct 2012 Location: NY Posts: 692 Trader Rating: (9) Feedback Score: 9 reviews	Lots of stores are no longer testing alternators due to the newer complex electronic ones giving constant 'bad' indications. Great for sales until the customer catches on. I actually had a hard time finding anyone other than Autozone here in NY. You can find rebuilt alts on ebay - look for good feedback, last one I bought was around $75 shipped and it was excellent.

10-25-2013, 11:32 AM	#9
*FaLKoN240* Super Moderator Join Date: Jun 2004 Location: SoCal Temecula Posts: 16,893 Trader Rating: (73) Feedback Score: 73 reviews	How old is the battery? What's your battery's resting voltage? What is the battery's voltage reading when running? When you rev it does the voltage go up? If the battery is below 12 volts with the car off, the battery is probably on it's way out. If you're running anything below 12V when the car is running the alternator is not returning enough voltage to your battery and is actually shortening the life of your battery. __________________ Best way to do business with me? Make your best offer FIRST.

10-25-2013, 01:10 PM	#11
shogunstyles15 Join Date: Aug 2013 Location: ca Posts: 8 Trader Rating: (1) Feedback Score: 1 reviews	Did you have any luck finding an auto parts store to test your alt in your area? You can go around in circles trying to trouble shoot it but the EASY way is to take the part out and take it to the store. Other than that you already have all the info you need. Its operating below acceptable levels so its time for a replacement. GL with your project.