Toyota FJ Cruiser Forum banner

1 - 17 of 17 Posts

·
Registered
Joined
·
77 Posts
Discussion Starter #1
On average what does the factory Alternator put out for voltage? Mine fluctuates between 13.2 to 13.6,,, seems like it should be a bit higher....
 

·
Registered
Joined
·
3,101 Posts
From previous posts on isolating potential alternator issues:

"Before starting any diagnostics, verify that the electrolyte level in all cells is correct (assuming a conventional wet-cell battery). Remove both battery clamps, and clean both the battery posts and the ID of the clamps with a ScotchBrite pad until clean, bright metal is exposed. If the clamps are corroded or deformed so they can't tightly clamp the battery posts, replace them.

First, let's verify battery voltage & charging system output. You'll need a good quality digital multimeter, capable of accurately resolving millivolts. This will not be a $15 swap-meet meter.

1. Measure battery voltage (at the battery clamps) after the vehicle sits overnight; it should be 12.6-12.9 volts at around 68F.
2. Measure battery voltage at 2,000 RPM, with no electrical loads turned on; voltage should be 13.2-14.8V.
3. Measure battery voltage at 2.000 RPM, with the headlights on, HVAC blower at MAX, and wet the windshield and turn the wipers on high speed; voltage should remain above 13.0V.
 

·
Registered
Joined
·
258 Posts
MP6989,

The alternator in my 2014 puts out the same voltage. Mid 13's at idle. When I first picked up my Cruiser I thought there might be a problem as I was expecting 14+ but apparently this is normal.
 

·
Registered
Joined
·
77 Posts
Discussion Starter #5
From previous posts on isolating potential alternator issues:

"Before starting any diagnostics, verify that the electrolyte level in all cells is correct (assuming a conventional wet-cell battery). Remove both battery clamps, and clean both the battery posts and the ID of the clamps with a ScotchBrite pad until clean, bright metal is exposed. If the clamps are corroded or deformed so they can't tightly clamp the battery posts, replace them.

First, let's verify battery voltage & charging system output. You'll need a good quality digital multimeter, capable of accurately resolving millivolts. This will not be a $15 swap-meet meter.

1. Measure battery voltage (at the battery clamps) after the vehicle sits overnight; it should be 12.6-12.9 volts at around 68F.
2. Measure battery voltage at 2,000 RPM, with no electrical loads turned on; voltage should be 13.2-14.8V.
3. Measure battery voltage at 2.000 RPM, with the headlights on, HVAC blower at MAX, and wet the windshield and turn the wipers on high speed; voltage should remain above 13.0V.
Thank you for the write up ,,, I’ve done all these steps and more. My Ultraguage confirms my meters readings to the T I was just expecting more from the charging system I guess,
 

·
Registered
Joined
·
77 Posts
Discussion Starter #6
I bought the HO alternator in 2010 and mine puts out 13.5 @ idle and 14.7 @ 2000RPM
Is this the Tacoma alt that seems to be popular with some of the fellas? Or and aftermarket ?
 

·
Registered
Joined
·
46 Posts
I think im going to buy a oem new or rebuilt ,I bought used on ebay from a low mileage tacoma wreck it was junk sent it back, Then a Rebuilt Denso installed it made noise swapped it out for another it had low voltage 13.0 -13.5 and my Alt gauge danced a bit my factory alt always ran 13.7-14.1,I got my dough back so im in the market for a 130 amp Toyota oem alternator as it can be trusted to perform for a long time just like the FJ.Dont bother with rebuilds from others its not worth it,On the Brite side I can now swap a fJ alt in 10 minutes.:smile
 

·
Registered
Joined
·
46 Posts
Double post by mistake.
 

·
Registered
Joined
·
854 Posts
YMMV but Mean Green has failed me on two other vehicles, three times. I won't throw that kind of money away on them again.
 

·
Admin
Joined
·
6,503 Posts
YMMV but Mean Green has failed me on two other vehicles, three times. I won't throw that kind of money away on them again.
6 yrs and going strong....

I'm one of the lucky ones I guess
:shrug03:


Sent from my SM-G950W using Tapatalk
 

·
Registered
Joined
·
1,399 Posts

·
Admin
Joined
·
6,503 Posts
1 - 17 of 17 Posts
Top