Need help with charging problem

M

Mustangl3

New Member

Dec 3, 2003

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willow grove, pa

Jul 28, 2005

#1

• Jul 28, 2005

• #1

what do the two wires going to the alternator do? Are they just power and ground? My battery isnt charging. One of the wires going to the alternator has 12V and the other has nothing so im assuming its a ground. Does this mean my alternator is bad or could it be soemthing else in the wiring of the alternator?
thanks for the help

 

K

Kilgore Trout

Fried or Broiled ?

10 Year Member

Mar 30, 2005

4,749

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134

Jul 28, 2005

#2

• Jul 28, 2005

• #2

AutoZone will test your alternator in the parking lot...

 

M

Mustangl3

New Member

Dec 3, 2003

242

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willow grove, pa

Jul 28, 2005

#3

• Jul 28, 2005

• #3

Well are they just going to measure voltage of the battery? I already know the alternator isnt putting out any voltage but i think it may be because of the wiring not the alternator itself. I guess i'll take a ride over there now. Is there any wiring diagrams online?

 

M

Mustangl3

New Member

Dec 3, 2003

242

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willow grove, pa

Jul 28, 2005

#4

• Jul 28, 2005

• #4

Autozone said my alternator was fine, but that cant be right because my battery was only putting out 10 volts when they put a load on it. Is there anything else beside the alternator, like a voltage regulator or something that controls the alternator. My car only has 46k miles on it and i dont have anything that drains extra power. And if anyone knows where i could get a wiring diagram that would be great.

 

N

n0v8or

10 Year Member

Aug 23, 2003

604

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Rhode Island

Jul 28, 2005

#5

• Jul 28, 2005

• #5

There should be three wires connected to your alternator:
Black / orange stripe - output to charge the battery (~12.8V for a fully charged battery; 14V-16V during charging)
Yellow / white stripe - system voltage sense wire (with key off, 12V-13V at all times unless ALT fuse is blown)
Lt green / red stripe - to alternator trouble lamp (12V -16V only in the RUN key position)
Ground connection is made through the case, not separately wired.

The voltage regulator is internal (built into the alternator).

 

M

Mustangl3

New Member

Dec 3, 2003

242

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willow grove, pa

Jul 28, 2005

#6

• Jul 28, 2005

• #6

Ok here's what happened when i tested the wires:

yellow/white 0V with key off....5mV with key on
green/red 3mV with key off....12.3V with key on

So it sounds like the alt fuse is blown and possibly causing the problem. Where is it, I checked the manual but didnt see alternator anywhere?
Thanks man you might have saved me from wasting $200

 

N

n0v8or

10 Year Member

Aug 23, 2003

604

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39

Rhode Island

Jul 29, 2005

#7

• Jul 29, 2005

• #7

The 20A alternator fuse is located in the relay/fuse box located to the rear of the battery. See: http://members.cox.net/n0v8or/fuses_01_mustang.pdf
For a drawing of fuse locations.

 

M

Mustangl3

New Member

Dec 3, 2003

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willow grove, pa

Jul 29, 2005

#8

• Jul 29, 2005

• #8

Thanks a lot man the fuse was the problem