Question about 2001 GMC Yukon

3 Answers

Electrical Issues I have replaced 4 alternators in the last 2 years. They last for a while and then they start to fade. The needle on the voltage meter will bounce back and forth and the lights will dim like its going to dye. So far it has not but my battery is new and this alternator is only 4 months old. All connections are good. Any ideas?

Posted by on

  • yadayada
    yadayada May 11, 2010

    Have you checked the connectors to the alternator?

×

3 Answers

  • Level 1:

    An expert who has achieved level 1.

  • Contributor
  • 1 Answer

Dont have either, I have noticed that when the truck is warming up the voltage will go down with acceleration and if I let off the gas it pops up. I do not have any loss of power from the motor with this.

Posted on Nov 15, 2008

Yes they are all fine.

Posted on Nov 05, 2008

  • Level 1:

    An expert who has achieved level 1.

    Corporal:

    An expert that hasĀ over 10 points.

    Problem Solver:

    An expert who has answered 5 questions.

  • Contributor
  • 9 Answers

Do you have amp and subs?????

Posted on Oct 29, 2008

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

Ok so if changing the PCM works you are the greatest and a heck of a lot smarter than people in the parts business


Well, all I'm saying is that the PCM is what regulates the voltage. There could be other electrical issues that are causing whatever problem you have. You haven't really stated what your symptoms were or what led you to the alternator. A damaged or broken wire between the PCM and the alternator can cause this issue. Wet or corroded connections at the alternator or PCM could as well. You can even get low voltage output if there is a very heavy load on the electrical system such as a short in the wiring. Any of these could cause these issues. I worked as a service writer for a major auto service center for 5 years. I've seen many electrical problems. Most are simple - battery/alternator/fuses, etc. But if they get into the wiring harness, most mechanics will stare at it like a monkey doing a math problem. They are trained, for the most part, for component replacement. They ASSUME the wiring to be ok unless they see obvious damage. This is why there is an entire submarket that many do not know about - auto electric repair shops. These guys are specialists in wiring issues. Replacing a PCM is something I would only do as a last resort.

Mar 06, 2015 | 1991 Dodge Dakota

1 Answer

Electrical Issues B2200


Your alternator is not yet doing anything. Minimum voltage, even with all accessories on, should be around 13.5 volts. Check all fuses, connections, grounds, and wiring. Have the alternator tested if you find nothing amiss.

Dec 03, 2012 | 1988 Mazda B2200

1 Answer

Battery light goes on and off


Your running the alternator on borrowed time as its a matter of time before the battery dies and needs replacement along with the old alternator. The light is indicating something wrong with the electrical system. A simple test at your favorite auto store capable of checking the battery/alternator system will reveal what's wrong or you can perform some simple measurements of battery voltage to determine the issues - the alternator is due for replacement and possibly the battery if it was allowed to operate with the battery light going on and off for a long time otherwise the alternator is on its last legs unless you can find loose connections on the alternator.

Usually alternators wear out; the brushes wear down after so many thousands of miles where they begin to lose physical contact and intermittently turn on the low voltage indicator warning you of electrical power problems. Measuring at the battery terminals should show battery voltage around 12.5v+, engine idling 13.5v+, above idling 14.3v+. If the last two voltages don't vary above battery voltage then the alternator is faulty. Remove it for testing before replacement. With so many miles on it, its due for replacement.

Oct 16, 2011 | BMW 325 Cars & Trucks

1 Answer

My 2005 Pontiac Sunfire has had several problems over the past couple of months. When I was driving all my gages went to zero when I would start to break. After I started moving again they would go up....


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.
======================================================================
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

Sep 05, 2011 | 2005 Pontiac Sunfire

1 Answer

Check engine light comes on and voltage gage drops below 9 volts, the battery gets drained in the process, battery is not charging. Checked the alternator and it checks out good.


There may be a no charge state in this case, or internal issues with your battery. I recommend checking the charging system and its corrosponding parts/sectors. Use the procedure below to isolate this issue.


Wear protective eye wear and clothing and remove all jewelry when checking your battery and charging system. Jewelry is a good conductor of electricity and is not recommended. Most batteries wear out every 3 to 5 years and need to be replaced. Always replace your battery with an equal replacement battery to assure proper operation. Automotive batteries have a +positive terminal (red), - negative terminal (black). Electricity is stored in the battery and then supplied to the vehicle when the engine is not running. While the engine is running the vehicles alternator charges the battery for future use. (Note: never disconnect the battery while the engine is running. If the battery cable is disconnected from the battery a spark can be generated which can cause the battery to explode or a major electrical malfunction to occur.)


To check a battery surface voltage, remove the positive terminal protective cover. Connect the +positive side meter lead (red) to the positive side battery terminal. Connect the - negative (black) side meter lead to the negative battery terminal. With the vehicle not running and the car sitting over night the battery voltage should be between 12.5 and 12.8 volts.(You will need to use a voltmeter for this testing procedure)


The alternator is rotated by a drive belt driven by the vehicles engine while it is running. Electrical voltage and amperage are generated to recharge the battery and supply voltage to the electrical system of the car. The alternator is held in place with mounting bolts. There is a main electrical wire on the rear of the alternator that supplies voltage to a main voltage junction box. If your alternator is not charging properly, your battery will slowly drain down from operating all the electrical systems in your car and stop the car from running.(most non charge states will be the cause of a loose belt or a low tension rate, due to a mis-adjusted alternator. make sure you have enough tension in the belt for full rotation of the alt pulley)


Next, you will need to check the alternators output with the Amp meter.

Testing the amperage output of the alternator is good for measuring the amount (not the level) of voltage the alternator can produce. This test can be tricky because if the alternator is weak it can still show it as producing amperage. Which is good, but if the voltage is low, it will still allow the battery to go dead. To check the amperage output of an alternator an amp meter is needed. Once the meter is connected start the engine. Next turn on all electrical accessories and raise the engine idle to about 1200 RPM. The alternator should output the max amperage it was designed to produce. Example: a 90 amp alternator should output about 88 amps. Note: An alternator cannot sustain maximum output for long periods of time. If the alternator is forced to operate at maximum output it will overheat and fail. An alternator is designed to operate at max amperage output only for a reasonable amount of time.

((Connect the voltage meter lead the same way you would in a battery static voltage check, Start engine (do not drive) at engine idle the voltage should be between 13.6 to 14.3 volts. If not the alternator may need replacing.)))

Apr 23, 2011 | 1996 Jeep Grand Cherokee

1 Answer

I have a 1997 Chevy Malibu (140K miles). The car was well maintained by prior owner. I have experienced the antitheft problem where I get locked out and have to wait 10-15 minutes. That has occurred...


i to have had some FUN with this darn system and replaced ignition cylnder(dealer has to program)can help usally for a few years ....but i dont want to swaer thats the samething causeing yours......feel free to repost

Dec 21, 2010 | 1997 Chevrolet Malibu

1 Answer

I have replaced the alternator in our windstar twice in the last several years I had to replace the windshield wiper motor 3 months ago. My battery is 2 years old. Now the alternator & battery are dead...


well the good thing is if there is a spike the battery will take it before other electrical componets check in the distribution box for bad relays & fuses

Jun 27, 2010 | Cars & Trucks

2 Answers

Charging gauge bouncing back and forth starts after jump


sounds like a shorted field in the alternator

Nov 07, 2009 | 1981 Ford F 150

2 Answers

92 ranger - piece of **** rebuilt starter ?


run scanner for trouble codes, some auto parts store will do this for free, check starter solenoid, check voltage at battery , 12+volts not started ,  14+ amps when running 

Oct 04, 2009 | 1992 Ford Ranger

1 Answer

Alternator problem


Buy a OEM alternator, preferably one from the dealer. Many alternators found at parts stores are rebuilt used ones.

Aug 22, 2008 | 2001 Ford Taurus

Not finding what you are looking for?
2001 GMC Yukon Logo

69 people viewed this question

Ask a Question

Usually answered in minutes!

Top GMC Experts

yadayada
yadayada

Level 3 Expert

60769 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

21949 Answers

Jeff Turcotte
Jeff Turcotte

Level 3 Expert

6811 Answers

Are you a GMC Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...