Main IndexAuto Repair Home Search Posts SEARCH
POSTS
Who's Online WHO'S
ONLINE
Log in LOG
IN







Check Charging System Light On


  Email This Post



kingjim9
User

Jul 24, 2010, 12:23 AM

Post #1 of 9 (16023 views)
Shortcut
Check Charging System Light On Sign In

On a 2006 Ford Taurus 3.0 L engine, the 'Check Charging System' Light came on on the dashboard. At the time it was at night so the headlights were on as well as the A/C, radio, etc.

I tested the voltage on the battery with the vehicle off and got 12.79 volts, then I started it up and got 12.5 volts. With the headlights on the reading was around 12.45 volts. At no time during the testing did the dashboard light come on, it only comes on occasionally while driving and stays on for around 15-20 seconds or so. It seems as if the light is more likely to come on with the A/C running that without it.

The battery was replaced probably around 8 months ago, and the wire running off the alternator looks in tact completely and is tightened down all the way. There's also another wiring harness going to the alternator which i think controls the voltage regulator and it's also on all the way. I was thinking it could be a bad alternator, what do you guys think?

Also how difficult is it to replace on this vehicle, it looks pretty straightforward but looks can be decieving sometimes!

Thanks,

-Jim


Hammer Time
Ultimate Carjunky / Moderator


Jul 24, 2010, 8:12 AM

Post #2 of 9 (16017 views)
Shortcut
Re: Check Charging System Light On [In reply to] Sign In


Quote
I tested the voltage on the battery with the vehicle off and got 12.79 volts, then I started it up and got 12.5 volts



You have already tested the charging system and it failed. Why are you still looking?




~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



kingjim9
User

Jul 24, 2010, 3:21 PM

Post #3 of 9 (16011 views)
Shortcut
Re: Check Charging System Light On [In reply to] Sign In

I figured the problem was the alternator, but the first time the dashboard light came on, my dad had Sears test the system and they came back and told him that everything's fine and that Ford's Alternators rarely go bad. They went on to say that the light probably came on because it was a hot day.

I didn't buy any of that and thats why i tested it myself after he got home, i figured it should be putting out at least 13 volts at idle.

Is this job as straightforward as it looks? remove the wires, remove the belt, remove the mounting bolts, etc. It didn't look like there would be anything in the way but i just wanted to get an expert's opinon.


Hammer Time
Ultimate Carjunky / Moderator


Jul 24, 2010, 3:35 PM

Post #4 of 9 (16008 views)
Shortcut
Re: Check Charging System Light On [In reply to] Sign In

The light is controlled buy the voltage which is integral to the alternator. Your alternator isn't charging so your first step is to replace the alternator and see if you still have any problems




~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



Vincent
New User

Jul 25, 2010, 10:04 AM

Post #5 of 9 (15996 views)
Shortcut
Re: Check Charging System Light On [In reply to] Sign In

Do the following tests and post back the results. Know that amperage test is almost always overlooked when test an alternator. Even if voltage is within threshold what good is voltage with the (PUSH) from amperage? Alternator voltage test

Make sure all your accessories and lights are turned off. Have an helper rev the engine up 2500 rpm. With a multimeter set on the DC scale measure the voltage across the battery terminals. Make sure the red lead of the multimeter is on the positive battery terminal and the black lead is on the negative battery terminal. With the engine at 2500 rpm’s the voltage reading on the meter should read from 13.5 volts to 14.4 volts. It’s necessary for an alternator to generate a larger voltage than the battery's rated voltage to overcome the internal resistance of the battery. If the voltage reading on the voltmeter is 12 volts or less you could have a failed alternator.

Alternator amperage test Connect the positive lead of the multimeter to the positive output on the rear of the alternator. Now connect the negative lead of the multimeter to the negative output of the alternator. With the engine running turn on all your electric accessories and lights and raise the idle to 1200 rpm. Read the meter. The alternators amperage output must never reach its maximum available output. (Example a 90 amp alternator should run no higher than 88 amps.) If an alternator is producing it's maximum capacity amperage, it will overheat and fail. Do the following tests and post back the results. Know that amperage testing is almost always overlooked when testing an alternator. Even if voltage is within threshold what good is voltage without the (PUSH) from amperage? Alternator voltage test

Make sure all your accessories and lights are turned off. Have an helper rev the engine up 2500 rpm. With a multimeter set on the DC scale measure the voltage across the battery terminals. Make sure the red lead of the multimeter is on the positive battery terminal and the black lead is on the negative battery terminal. With the engine at 2500 rpm’s the voltage reading on the meter should read from 13.5 volts to 14.4 volts. It’s necessary for an alternator to generate a larger voltage than the battery's rated voltage to overcome the internal resistance of the battery. If the voltage reading on the voltmeter is 12 volts or less you could have a failed alternator.

Alternator amperage test Connect the positive lead of the multimeter to the positive output on the rear of the alternator. Now connect the negative lead of the multimeter to the negative output of the alternator. With the engine running turn on all your electric accessories and lights and raise the idle to 1200 rpm. Read the meter. The alternators amperage output must never reach its maximum available output. (Example a 90 amp alternator should run no higher than 88 amps.) If an alternator is producing it's maximum capacity amperage, it will overheat and fail.

Do the following tests and post back the results. Know that amperage test is almost always overlooked when test an alternator. Even if voltage is within threshold what good is voltage with the (PUSH) from amperage? Alternator voltage test

Make sure all your accessories and lights are turned off. Have an helper rev the engine up 2500 rpm. With a multimeter set on the DC scale measure the voltage across the battery terminals. Make sure the red lead of the multimeter is on the positive battery terminal and the black lead is on the negative battery terminal. With the engine at 2500 rpm’s the voltage reading on the meter should read from 13.5 volts to 14.4 volts. It’s necessary for an alternator to generate a larger voltage than the battery's rated voltage to overcome the internal resistance of the battery. If the voltage reading on the voltmeter is 12 volts or less you could have a failed alternator.

Alternator amperage test Connect the positive lead of the multimeter to the positive output on the rear of the alternator. Now connect the negative lead of the multimeter to the negative output of the alternator. With the engine running turn on all your electric accessories and lights and raise the idle to 1200 rpm. Read the meter. The alternators amperage output must never reach its maximum available output. (Example a 90 amp alternator should run no higher than 88 amps.) If an alternator is producing it's maximum capacity amperage, it will overheat and fail. Do the following tests and post back the results. Know that amperage test is almost always overlooked when test an alternator. Even if voltage is within threshold what good is voltage with the (PUSH) from amperage? Alternator voltage test

Make sure all your accessories and lights are turned off. Have an helper rev the engine up 2500 rpm. With a multimeter set on the DC scale measure the voltage across the battery terminals. Make sure the red lead of the multimeter is on the positive battery terminal and the black lead is on the negative battery terminal. With the engine at 2500 rpm’s the voltage reading on the meter should read from 13.5 volts to 14.4 volts. It’s necessary for an alternator to generate a larger voltage than the battery's rated voltage to overcome the internal resistance of the battery. If the voltage reading on the voltmeter is 12 volts or less you could have a failed alternator.

Alternator amperage test Connect the positive lead of the multimeter to the positive output on the rear of the alternator. Now connect the negative lead of the multimeter to the negative output of the alternator. With the engine running turn on all your electric accessories and lights and raise the idle to 1200 rpm. Read the meter. The alternators amperage output must never reach its maximum available output. (Example a 90 amp alternator should run no higher than 88 amps.) If an alternator is producing it's maximum capacity amperage, it will overheat and fail.

(edited out MANY hyperlinks - not allowed)


(This post was edited by Tom Greenleaf on Jul 25, 2010, 10:11 AM)


Hammer Time
Ultimate Carjunky / Moderator


Jul 25, 2010, 10:11 AM

Post #6 of 9 (15989 views)
Shortcut
Re: Check Charging System Light On [In reply to] Sign In

Vincent,

If your just going to come in here and paste info copied from other sites, it's not very helpful.

All these amperage tests are pretty much useless since the charging system has no voltage output at all.




~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



Tom Greenleaf
Ultimate Carjunky / Moderator


Jul 25, 2010, 10:17 AM

Post #7 of 9 (15985 views)
Shortcut
Re: Check Charging System Light On [In reply to] Sign In

You don't need to go nuts. If it can't put out at least 13v with everything running, lights, RWD, blower and all connections and battery known good not just known new(er) belt it snug enough, then the alternator brushes, diodes or regulator isn't up to par. Diodes can allow just enough charge to keep you going but won't overcome full use of several items.

What will screw the whole thing up is some funky aftermarket something drawing too much or wires messed up. You can buy those components separately but usually best to just swap it out for new or a quality rebuilt with warranty,

T
_________________________________________
Long retired now


kingjim9
User

Jul 27, 2010, 2:25 PM

Post #8 of 9 (15968 views)
Shortcut
Re: Check Charging System Light On [In reply to] Sign In

Thanks guys, just to let everyone know I replaced the alternator and now i'm getting 13.6 volts at idle. The light no longer comes on! I replaced the belt too just since it was starting to get some heat cracks in it. Thanks for the help.

It still gets me that sears would say nothing's wrong with it if the light was flashing off and on everynow and then. Unless it just happened to test normal for the few minutes they looked at it!


Tom Greenleaf
Ultimate Carjunky / Moderator


Jul 27, 2010, 7:01 PM

Post #9 of 9 (15962 views)
Shortcut
Re: Check Charging System Light On [In reply to] Sign In

Thanks for posting the fix kingjim9. Sorry about "vincent" just posting crap from other sites on this.

Hey - I don't know why it was tested good at Sears as you said. Fluke maybe that it was working just then or perhaps tested wrong somehow but I don't want to blame a chain on one event.

Brushes can be intermittent but usually when they are the issue it's all or nothing back and forth possible at first. Other items don't heal TMK,

T
_________________________________________
Long retired now




Check Charging System Light On


  Email This Post
 
 






Latest Forum Post
I have a 95 Mazda B2300 extended cab. i know its pretty much the same as a Ford ...
Please, any advice is helpful! First, I drive a 1997 VW Passat with 40K (origin...
I have a 2001 Toyota Camry that keeps blowing the gauge fuse. I have put an engi...
I have a 1986 Cadillac Fleetwood Brougham 5.0 the no charges light came on so I...
2005 Nissan Sentra four cylinder 1.8F. Several times now the engine just quit...
2000 Ford Focus wagon 2.0 4 cyl. manual trans. 200,000 km Hello, car runs fine w...

Feed Button


Used Car Search
Used Car Price Ranges:
Under $5,000
$20,000
$35,000

$10,000
$25,000
$40,000
$15,000
$30,000
$45,000
Over $45,000
Search used Cars By Manufacturers:
Used Acura
Used Audi
Used BMW
Used Buick
Used Cadillac
Used Chevrolet
Used Chrysler
Used Dodge
Used FIAT
Used Ford
Used GMC

Used Honda
Used Hyundai
Used Infiniti
Used Jaguar
Used Jeep
Used Kia
Used Land Rover
Used Lexus
Used Lincoln
Used Mazda
Used Mercedes-Benz

Used MINI
Used Mitsubishi
Used Nissan
Used Porsche
Used Saab
Used Scion
Used Subaru
Used Suzuki
Used Toyota
Used Volkswagon
Used Volvo
2010 Honda Civic
$15,770
2004 Jeep
$8,991
2012 Mustang
$22,990
1997 Honda Cr-V
$4,490
2010 Toyota Prius
$17,496
2010 BMW 328
$26,980




Automotive Forum Categories
Automotive Repair
Auto Body Repair and Refinishing
AC Auto Repair Help Forum
Automotive Wiring and Electrical

Auto Insurance and Car Financing
Automotive World
Brake Systems
Car Stereo Repair Advice
Car Troubleshooting
Engine and Car Noises
Engine Fault Codes
Engine Troubleshooting
Exhaust System Repair

Steering and Suspension
Tricks of the Trade
General Discussions
Car Shows and Events
The Bargin Bin
Motor Vehicle Inspection
Car Care Tips
Traffic Ticket Help
Car Racing

Gasoline, Motor Oils, Concept Cars
Remote Control Cars and Vehicles
Truck Repair
Truck Repair Advice


Truck Engine Repair
Truck Suspension Repair
Motorcycle Repair
Motorcycle and ATV Repairs

Motorcycle Body Repair
Motorcycle Clutch Repair
Motorcycle Engine Repair
Motorcycle Seat Repair
Car Forum Posts - Sitemap


Search for (options) Privacy