2000 sunfire charging system

Hi George,
I need year--make--model--engine size.
Usually the alternator needs excite voltage or no charge. The alternator bat terminal should be hot all the time, even with key off, if it isn't, something wrong with that wire circuit.

Did you have the charging system diagnosed or did you just guess at it being the alternator . The charging system is computer controlled . The starter isn't working because low power , battery dead . Is there B+ voltage at the wire on the back of the alternator .B+ voltage at pin 3 at the connector pluged into the alternator .
Charge the battery use a volt meter an test for B+ voltage at the places i mention . No check engine light ? DTC'S - diagnostic trouble codes stored .
Ford Smart Charge System Alternator Not Charging
Ford PCM controlled alternator testing

your voltage is only going to be what ever your batt. is charged up to proper way to check alt out put is to disconnect batt,use volt meter from + lead to poss cable - lead to ground cable, voltage sould be 12.9 to14.0

Your car's symptoms (voltage fluctuations under load that shouldn't happen) seem to
strongly indicate that your voltage regulator has failed. The voltage regulator is the component
that regulates voltage coming from the alternator, and which is supplied to the rest of the car.
Your new belt tensioner indicates to me (and should have to your mechanic) that the
alternator and/or voltage regulator weren't able to operate properly, and a faulty belt tensioner
has killed more than one car's alternator/voltage regulator.
Your do not need new headlights. Do fix the turn signals.

In the 2005 Sunfire, the voltage regulator is an integral component of the alternator, and is
not separately serviceable. So your 2005 Sunfire needs a new alternator.

2005 Pontiac Sunfire Alternator - Duralast Part Number: DL2305-15-4 $199.99 available at:
http://www.autozone.com/autozone/parts/2005-Pontiac-Sunfire/Alternator/_/N-jmqtpZ93xme

The national parts chains (Advance Auto Parts, AutoZone, Pep Boys) will (for free) administer
a "Charging System Test." Which will telly you for sure that your alternator/voltage regulator
is bad. Do this before replacing alternator, since its a pricy part in the 05 Sunfire.

Just in case, Here's the 2005 Sunfire manual entry on (a) Diagnosis & testing the alternator, and
(b) replacement of the alternator

Alternator replacement is a do-it-yourself project, though you may need to get a
"Serpentine Belt Kit" on your favorite parts store's loan-a-tool program to remove/re-install the serpentine (drive) belt.
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Diagnosis & Testing - 2005 Pontiac Sunfire Alternator


Alternator Load Test

1. With the engine running, turn on the blower motor and the high beams ( or other electrical accessories to place a load on the charging system).

2. Increase and hold engine speed to 2000 rpm.

3. Measure the voltage reading at the battery.

4. The voltage should increase at least 0.5 volts from the voltage test. If the voltage does not meet specifications, the charging system is malfunctioning.
NOTE
Usually under and overcharging is caused by a defective alternator, or its related parts (voltage regulator), and replacement will fix the problem; however, faulty wiring and other problems can cause the charging system to malfunction. Many automotive parts stores have alternator bench testers available for use by customers. An alternator bench test is the most definitive way to determine the condition of your alternator.




Alternator No-Load Test

1. Connect a tachometer to the engine.
CAUTION
Ensure that the transmission is in Park and the emergency brake is set. Blocking a wheel is optional and an added safety measure.


2. Turn off all electrical loads (radio, blower motor, wipers, etc.)

3. Start the engine and increase engine speed to approximately 1500 rpm.

4. Measure the voltage reading at the battery with the engine holding a steady 1500 rpm. Voltage should have raised at least 0.5 volts, but no more than 2.5 volts.

5. If the voltage does not go up more than 0.5 volts, the alternator is not charging. If the voltage goes up more than 2.5 volts, the alternator is overcharging.
NOTE
Usually under and overcharging is caused by a defective alternator, or its related parts (regulator), and replacement will fix the problem; however, faulty wiring and other problems can cause the charging system to malfunction. Many automotive parts stores have alternator bench testers available for use by customers. An alternator bench test is the most definitive way to determine the condition of your alternator.


6. If the voltage is within specifications, proceed to the next test.



Voltage Test

1. Make sure the engine is OFF , and turn the headlights on for 15-20 seconds to remove any surface charge from the battery.

2. Using a DVOM set to volts DC, probe across the battery terminals.

3. Measure the battery voltage.

4. Write down the voltage reading and proceed to the next test.



Removal & Installation - 2005 Pontiac Sunfire Alternator


2.2L (VIN 4) Engines

1. Before servicing the vehicle, refer to the precautions section.

2. Remove or disconnect the following:

Negative battery cable

Accessory drive belt

Alternator mounting bolts

Alternator electrical connectors

Alternator





To install:

1. Before servicing the vehicle, refer to the precautions section.

Alternator. Torque the upper bolts to 37 ft. lbs. (50 Nm) and the lower bolt to 22 ft. lbs. (30 Nm).

Alternator electrical connectors

Accessory drive belt

Negative battery cable





2.2L (VIN F) Engines

1. Before servicing the vehicle, refer to the precautions section.

2. Remove or disconnect the following:

Negative battery cable

Accessory drive belt

Alternator mounting bolts

Alternator electrical connectors

Alternator





To install:

1. Install or connect the following:

Alternator. Torque the bolts to 16 ft. lbs. (22 Nm).

Alternator electrical connectors

Accessory drive belt

Negative battery cable

Battery might seem fine on a routine check, but the crancking amp power is not there anymore, seems that your alternator is not charging it anymore, have the alternator checked and replaced if needed, the battery might need replacing too.

It sounds like you have a charging problem-alternator is not recharging batt when drive, batt will only go so far before it runs out then you get your symtoms. you would need a volt meter to double check this. Fully charged batt will be about 12.7volts once car is started and running you should see about 13.8 to 14.2 volts at batt terminals if alt. is chariging batt. the other item that can cause this is the volatge regulator that controls alt. which are sometimes built-in alternator and sometimes they are external to alternator. and of course make sure your belt is turning alternator to allow it to work. One other small note if you do the engine running test-somtimes- if your car idles low(600 or 700 rpm) you need to give a little throttle (1000-1200rpm) to make sure alternator is turning fast enough for output test.

Hey. You need to check the volatage on the battery with car switched on. Anything less that 14 volts that means that batt is not charging. ALso could be a faultuy batt considering youve had the alt changed .

11.50 volts won't be enough potential to overcome the batteries 12 volt standing charge.

Either your alternator is shot...which you can check by going to an Autozone and having a free system check. Or your battery is already going bad and not sending enough voltage to the alternator to make the 13.8-15.8 volts it should be making.

If the alternator is the culprit a good mechanic will swap it out for a fairly low price and save you a lot of headaches.

Good luck and be careful.

Sounds like you may need an alternator.
If the batt is ok, could be the alt going out.
A local pep boys or equivalent can check free or inexpensively...
The voltage regulator is built in to the alternator... so if you change the alternator, you change the regulator too.
k

I would check the plug going into the alternator. They have been known to fail at times. I would also check the fuse for the alternator if equipped.