Charging voltage

Tiny
GONDAR PERSON
  • MEMBER
  • 2006 FORD TAURUS
  • 6 CYL
  • 100,000 MILES
With the car the battery is 12.3 volts.
When you start the car drops to 11 volts.
Disconnecting the plug at the alternator
will bring back voltage to 12 plus at the battery.
What is causing the drop to 11 volts, when
removing the little connector?
Do you
have the same problem?
Yes
No
Tuesday, January 4th, 2022 AT 8:02 PM

31 Replies

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 108,005 POSTS
The alternator isn't charging the battery. When you start the engine, the electrical draw from all the different modules, lights, fuel pump, and so on all require power to work. Since the alternator isn't producing voltage, the battery is working alone. Thus, you have a lower voltage.

First, confirm fuses are good. If you look at the last three pics below, they show fuses related to the alternator. Check them. Make sure there is power to and from them as well. Here is a link you may find helpful. Note, there is a 175-amp fuse tied with the alternator as well. See pic 4 below. I didn't highlight it because I feel it likely isn't the cause but check it if you find a power issue to fuse 26 in the under-hood fuse box.

https://www.2carpros.com/articles/how-to-check-a-car-fuse

Since you already checked the voltage, it sounds like the alternator needs replaced, especially if the fuses check good. You can remove it and have it bench tested at most parts stores. They will be able to confirm if it is working. Also, most will do it free of charge.

Here is a link that explains in general how one is replaced. You can use this to help guide you through the replacement process.

https://www.2carpros.com/articles/how-to-replace-an-alternator

If you look at the two pics below, they are from the manual specific to your vehicle. When you work on the alternator, please make sure the battery is disconnected first. (Pics 1 and 2) Pic 3 is the wiring schematic for the charging system. I added it for reference.

Let me know what you find or if you have questions.

Take care,

Joe

See pics below.

Was this
answer
helpful?
Yes
No
+1
Tuesday, January 4th, 2022 AT 9:10 PM
Tiny
GONDAR PERSON
  • MEMBER
  • 25 POSTS
Whoa Joe. That was quit!

I will check everything again, in a few but in the meantime, my curiosity
is why the voltage on the alternator and battery goes up to 12 volts when
I disconnect C1104, the connector on the alternator.

When I check voltage at the main cable on the
alternator that goes to Fuse B in your pics
1: With connector ON = 10-11 Volts
2: With connector OFF = 12.3 Volts.

1000 of thanks again!
You people responded very fast, I will promote
this web place on the net.
Was this
answer
helpful?
Yes
No
Wednesday, January 5th, 2022 AT 5:12 AM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 108,005 POSTS
Hi,

That connects to the GEM (generic electronic module). You are drawing more power when it's connected because you have connected more electronics.

In this case, since it doesn't go above 12.3v, there is a good chance the alternator is bad. I would remove it and bench test it to confirm. Most parts stores will do it free of charge.

Let me know if you have other questions or if I can help in any way.

Take care,

Joe
Was this
answer
helpful?
Yes
No
Wednesday, January 5th, 2022 AT 3:51 PM
Tiny
GONDAR PERSON
  • MEMBER
  • 25 POSTS
Joe, the alternator will be here by Wednesday (Ordered Online)
However, I found conflicting info on the service manual.
Can you let me know "The Right Torque" for the 3 indicated bolts?
Idler wheel will be replaced, but the wheel of the Tensioner needs to re-tied-up.
Thanks.
Was this
answer
helpful?
Yes
No
Monday, January 10th, 2022 AT 8:29 AM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 108,005 POSTS
Hi,

Did you have the alternator bench tested to confirm? As far as the torque specs, the only one indicated in the manual for the tensioner is 18 ft/lb. The idler pulley is 35 ft/lb.

Let me know if you have other questions.

Joe
Was this
answer
helpful?
Yes
No
Monday, January 10th, 2022 AT 3:40 PM
Tiny
GONDAR PERSON
  • MEMBER
  • 25 POSTS
No matter what, that alternator is making noise when you turn it by hand.
Now, this pic shows what my manual indicates, however the one marked with
the arrow, lost pressure by mistake, need to tie back, 18 -20?
Was this
answer
helpful?
Yes
No
Monday, January 10th, 2022 AT 5:40 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 108,005 POSTS
Hi,

Yep, that's the tensioner. 10 to 20 ft/lbs should be fine.

Let me know if I can help.

Joe
Was this
answer
helpful?
Yes
No
Monday, January 10th, 2022 AT 9:03 PM
Tiny
GONDAR PERSON
  • MEMBER
  • 25 POSTS
Thank Joe, the alternator is in and also a new Idler Pulley.
Voltage at the battery is now 14 Volts.
However, there is something now that it didn't do before, when I reached 40 MPH
the motor starts with hiccups, the car will not shut off, but also on a little hill will do
that again, I thought was the transmission, but I see that the transmission is switching okay
and even parking when it is cold may do that. Do you think bad gasoline from Walmart have something to do with it?
Was this
answer
helpful?
Yes
No
Thursday, January 13th, 2022 AT 7:28 AM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 108,005 POSTS
Hi,

It's possible that the fuel is bad. By chance, has the engine light turned on? Let me know. Also, just do a quick inspection to make sure no vacuum hoses were left off or damaged as well as electrical connectors. Since it happened after the work, it's likely something really simple.

Here is a link that explains how to locate a leak:

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

Take care,

Joe
Was this
answer
helpful?
Yes
No
+1
Thursday, January 13th, 2022 AT 6:59 PM
Tiny
GONDAR PERSON
  • MEMBER
  • 25 POSTS
Okay, I can't just read without saying Thanks Again
Let's hope it gets a little warm outside, because we had some very cold days.
Was this
answer
helpful?
Yes
No
Friday, January 14th, 2022 AT 3:37 AM
Tiny
GONDAR PERSON
  • MEMBER
  • 25 POSTS
What I got from my Scanner: P0306 Cylinder number 6 misfiring.
Was this
answer
helpful?
Yes
No
Friday, January 14th, 2022 AT 10:20 AM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 108,005 POSTS
That is specific to that cylinder only. Make sure the spark plug wire at the coil wasn't damaged, shorting, or loose. Follow it from the coil to the plug.

Let me know what you find. I attached pics below showing the coil and engine cylinder locations for cylinder 6.

Take care,

Joe

See pics below.
Was this
answer
helpful?
Yes
No
Friday, January 14th, 2022 AT 9:04 PM
Tiny
GONDAR PERSON
  • MEMBER
  • 25 POSTS
I am sorry for bothering you so much.
The fact is I appreciated so much what you folks doing, that I created a
promotional video-clip located here: https://www.facebook.com/100004608636727/videos/418478300063163/

Also available on Facebook's Messenger for 2CarPros.

Hope you like it.
Was this
answer
helpful?
Yes
No
Friday, January 14th, 2022 AT 9:22 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 108,005 POSTS
You are no bother at all. That is excellent and thank you! I will send the link to the one guy in the pic, Ken. I know he will truly appreciate it.

Thanks again,

Joe
Was this
answer
helpful?
Yes
No
Friday, January 14th, 2022 AT 9:27 PM
Tiny
GONDAR PERSON
  • MEMBER
  • 25 POSTS
Thank you.
Was this
answer
helpful?
Yes
No
+1
Friday, January 14th, 2022 AT 9:42 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 42,544 POSTS
Wow! Thank you so much for the video. We are glad you like our service. My mom created it back in 1999.
Was this
answer
helpful?
Yes
No
Saturday, January 15th, 2022 AT 11:17 AM
Tiny
GONDAR PERSON
  • MEMBER
  • 25 POSTS
Thanks Ken, I did it for you and feel free to do whatever you want with it, it is
on my wall too on Facebook (Gondar Person ).
Just stopped by to tell Joe that the car will have to wait, look at the weather map.
I am on Roanoke, Virginia, and old coming apart. LOL Take care.
Let's wait until this weather warms up a little bit.
Was this
answer
helpful?
Yes
No
Saturday, January 15th, 2022 AT 3:22 PM
Tiny
GONDAR PERSON
  • MEMBER
  • 25 POSTS
The conditions today the 17, as you can see, we had about 4 to 6 inches.
Still, I went and cleaned the car a little bit and fire-up.
Like always, it fires up in one second with no hesitations or anything.
Was this
answer
helpful?
Yes
No
Monday, January 17th, 2022 AT 11:00 AM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 108,005 POSTS
Hi,

I plowed snow most of the day. Now, the wind is blowing it back on everything. Ugh! LOL

Were you able to check the spark plug wire for the cylinder misfire?

Let me know.

Joe
Was this
answer
helpful?
Yes
No
Monday, January 17th, 2022 AT 4:47 PM
Tiny
GONDAR PERSON
  • MEMBER
  • 25 POSTS
The wind is also bad here, so no, I always start the car every 2 days when not using it.
Wait until this snow goes down, I play in a bowling league, was also cancelled
for tomorrow Tuesday (Chickens LOL). If you noticed I did not even clean the car
completely, wind started to pick up, I let you know when I do it, maybe in the next 2 days
if weather permitted. In mean time sing. Raindrops Keep Falling on My Head.
Was this
answer
helpful?
Yes
No
Monday, January 17th, 2022 AT 7:19 PM

Please login or register to post a reply.

Sponsored links