Ford Expedition Check Charging System light

Tiny
BD1133
  • FORD EXPEDITION

Somebody else asked this question, but I did not see any response so I thought I would repeat the question since I am having the same problem. I have 2003 Ford Expedition with approximately 66,000 miles. About two weeks ago, check charging system warning started displaying and battery light coming on and off. Had my battery and alternator checked at a local auto store, on their recommendation I changed both as well as the belt. In spite of above changes, the battery light and warning is continuously on now. If I do not have to, I do not want to take it into the dealership for costly "diagnostic tests" and repairs. Does anybody know what may be causing this problem? Any and all recommendations are appreciated.

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Wednesday, September 12th, 2007 AT 10:18 PM

16 Replies

Tiny
RASMATAZ
  • MEMBER

Check all of the connectors they can melt causing a bed connection, ford had a big problem with this in the past. Also there is a fuse #34 you must test and check to see if the fusible links have power through them. Here is a guide and some diagrams to help us find the problem.

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

and

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

and

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

Please let us know what happens.

Cheers,

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Wednesday, September 12th, 2007 AT 10:38 PM
Tiny
ANTNEE3
  • MEMBER

I replaced my battery, but it did not fix. I noticed that when "Check Charging System" was on, I would have 12.1 volts, when it would go out, 13.9. While it sounds like an alternator problem, I thought it was weird that it could basically work, and then not work.

I have been driving the car without issue until last night. While driving, the car just completely stalled. Suddenly, I had the "Check Charging System", and battery light on. I pulled over, turned key, and the engine cranked over fast, and was not starting. If I turned the key off, removed it, replaced it, and restarted, no problem. I limped home doing this three different times. Now the battery light is on solid. Finally, though, I have a service engine soon light, so I should be able to get some trouble codes.

So on a whim I got a motorcraft alternator because I felt the alternator I got for it was to cheap and could be my problem. Wouldn't you know it? It worked and I am back on the road, it costs a little more but worth it.

Here it is on Amazon in case anyone has the same problem.

https://www.amazon.com/gp/product/B00HFLCCP8/ref=as_li_qf_sp_asin_il_tl?ie=UTF8&tag=2carprcom-20&camp=1789&creative=9325&linkCode=as2&creativeASIN=B00HFLCCP8&linkId=c98d8d6894558442c4c5bec440b93564

Thanks all!

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Monday, September 17th, 2007 AT 12:54 PM
Tiny
DHCHJHPH
  • MEMBER

I have a 2003 Ford Expedition doing the same exact thing. I noticed it did it more so when the air conditioner or heat was running like something was drawing the power down or something. Now it is doing it all the time mainly when I am accelerating. I to have had my truck not want to start, I had to take the key out and then reinsert it too in order to get it to start a couple of times now. Anyone? Please have an answer for me!

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Saturday, December 15th, 2007 AT 7:45 PM
Tiny
PCAVA57
  • MEMBER

From your description and based on a similar problem I had with my 2004 Expedition, I would suspect an intermittent partial short. Check the wiring harness at the alternator this is where it will melt the connector causing the problem.

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Thursday, March 20th, 2014 AT 12:40 AM
Tiny
XXDEADPOOLXX
  • MEMBER

Hi, My 2003 expedition just started having the same problem. It comes up, "check charging system" it has a brand new battery. Any help will help me a lot. Thank you!

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Thursday, February 18th, 2016 AT 2:56 PM
Tiny
2CARPROS KEN
  • ADMIN
  • 10,306 POSTS

I found this wiring diagram for you, look at the connector at the alternator to see if they have been over heated which will cause a bad connection. Also check the fusible links, here is a wiring diagram that will help.

Please let us know what you guys find so it will help others,

Best, Ken

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Tuesday, November 22nd, 2016 AT 12:30 PM
Tiny
DK78KK
  • FORD EXPEDITION

I have 2004 ford expedition 71000 miles, 5.4 engine. The check charging system light came on. Had it check at my parts store. Alternator was not charging, had it rebuilt by a local rebuild shop(good record), cleaned bat. Terminals, and load tested battery, all good. But the Light is still on and I have 14.5 volts with engine running. Any Idea's?

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Friday, December 16th, 2016 AT 3:50 PM (Merged)
Tiny
JET243
  • MEMBER

I have the same problem on my 2003 ford expedition I changed battery and alternator and battery/check charging system light will not turn off. I also verified the charger was charging the battery and the fuse was good. I could not find a manual. Does anybody know or have a wiring diagram that can tell me where the cable from the battery to the alternator splits off to and how it works with the fusible link(s)?

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Friday, December 16th, 2016 AT 3:50 PM (Merged)
Tiny
JW6937
  • MEMBER

I have the exact same problem. 2003 Expedition with about 71k miles on it. Alternator just went out on it. Replaced it with a new one, but the red battery dummy light stays on, & the message center is still showing the "Check Charging System" message? Tried installing a 2nd new alternator just in case, but the "Check Charging System" message is still there. Tested the output on the alternator & everything test perfectly. But no matter what I try, that darn "Check Charging System" message won't go away. Has anyone determined a fix to this issue yet?

FROM KEN: Check the solution below

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Friday, December 16th, 2016 AT 3:50 PM (Merged)
Tiny
MANUELXP@ADELPHIA.NET
  • MEMBER

I have the same problem but it is one step further, I am on my second alternator they ran a test of the first one and it wast fine but like I told them with it not carrying a load it could test good all day replaced it now the light is still on but engine dies right after it is jumped I did test battery low but still good. The vehicle does not hold the charge Does anyone know what fuses I should be looking at?

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Friday, December 16th, 2016 AT 3:50 PM (Merged)
Tiny
2CARPROS KEN
  • ADMIN
  • 10,306 POSTS

Hello Dk78kk,

It looks like the problem is the PCM or you have high resistance or a broken fusible link, here is a diagram below.

Please let us know what you find so it will help others.

Best, Ken

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Friday, December 16th, 2016 AT 3:50 PM (Merged)
Tiny
HEJLMAN
  • MEMBER

I have the same problem, intermittent warning for charging system. I have shot all the wires, grounds and tested the alternator for proper voltage, all is good. I think it may be the tensioner and or the belt causing it to slip ever-so slightly, just enough to cause the warning. I'll post again as soon as I swap them out.

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Thursday, December 29th, 2016 AT 9:56 AM
Tiny
CCBC65
  • MEMBER

I have a 2003 Expedition XLT with the 5.4 and 4WD. It has 293K miles and recently started having the same problem. Rebuilt original alternator at 185K miles. The rebuild went bad about 6 months ago and this time the Battery Light was on and the Check Charging System message came up, that didn't happen last time. After replacing the alternator, the Battery Light stayed on but everything was charging and working so I let it be. Two to three months ago, the Check Charging System message started coming up but the system was still charging fine. It started coming up more and more but I still couldn't find a problem but the last 3 weeks, it would not charge sometimes and died a few times while I was driving. When I tested the system, sometimes it worked, sometimes it didn't. Battery and alternator bench tested fine, parts store replaced alternator under warranty anyway. Still had the problem of not charging sometimes. Days of testing and investigation determined the fusible links were intermittently causing the system to not charge, when I moved them it would charge, when I moved them again it would not charge. I replaced the entire harness from the alternator to the battery and PCM and it's charging well now but the Battery Light is still lit and the Check Charging System message comes on as soon as I start the truck.

I have the service manuals and it said "Repair the high resistance in the B+ circuit 38" like Ken said above but I'm not sure what that means and thought it would be covered when I replaced the entire cable. Did I miss something?

Any suggestions why the Battery Light is still lit and the Check Charging System message still comes up?

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Thursday, May 4th, 2017 AT 7:49 PM
Tiny
CARADIODOC
  • EXPERT
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There are some defects that can be detected by the voltage regulator, which turns on the "Battery" warning light, even though charging voltage is within the acceptable range of 13.75 to 14.75 volts. The most common defect is one failed diode of the six inside the generator. The regulator detects that momentary dropout of one the three output phases. It responds to the lower voltage during that time by bumping the charging voltage up a little. You see the correct charging voltage. The regulator sees around 11 to 12 volts.

To add to the misery, Ford regulators can also turn the warning light on for an over-charge condition. When the regulator raises charging voltage in response to the dropout of the missing phase, it does that instantly, but when the two good phases come along, it takes some time before it brings the target voltage back down. That's why it might see something over 14.75 volts and turn the warning light on, while you measure a proper 13.75 to 14.75 volts.

Failed diodes are a permanent failure. That is found by performing a full-current load test with a professional load tester. It will show up as high "ripple' voltage, and the most current you'll be able to get is exactly one third of the generator's rated current. That's 30 amps from the common 90-amp generator, and that's not enough to run the entire electrical system under all conditions.

Another common failure is worn brushes, and those almost always ARE intermittent, at least at first. The mistake here is the testing has to be done while the problem is occurring. When the brushes make good enough contact to work, there is no defect to be found, so of course the system will test good. The testing has to be done while the problem is occurring.

The second consideration, after reading through the multiple posts here, is everyone did the obvious and replaced the generator, but the engineers unnecessarily complicated the circuit by involving the Engine Computer in what used to be a real simple system. It is very likely the computer set a diagnostic fault code, and that is triggering the warning message that is the common symptom here. Even when a wiring problem was found, and obviously affected system performance, the message didn't go away when the system resumed working. It is likely necessary to erase the fault code after the repair has been completed, and that will turn off the message.

What no one ever listed here was the test results. "Full-load output current" and "ripple voltage" are just as important as charging voltage. Most testers just show ripple voltage between "low" and "high" on a relative bar graph, but that is a major clue in this story.

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Thursday, May 4th, 2017 AT 9:28 PM
Tiny
CCBC65
  • MEMBER

I read somewhere of someone having the same problem with the battery light and the Check Charging System message because he put in a 130 amp alternator in an Expedition that originally had a 110 amp alternator and when he put a 110 amp alternator back in, the light and message went away. Has anyone else heard that? I'm going to call the parts store and see if I can swap back the 130A for the 110A.

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Friday, May 5th, 2017 AT 10:10 AM
Tiny
CARADIODOC
  • EXPERT
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Normally changing to a different current rating doesn't cause a problem, but with the addition of all the unnecessary computer controls, it's hard to know what will cause an issue. Just because the plugs and wires might be the same, there could be some other differences we don't know about.

The key points to understand is an AC generator, ("alternator" is a term copyrighted by Chrysler, but it's the same thing), is physically and electrically incapable of developing more current than it was designed to deliver. I can impress you with the theory if you want me to, but it's not relevant to my wondrous story. The next important point is the generator will only develop the amount of current needed by the electrical system, and no more. It's similar to running a lawn sprinkler on a garden hose. No more water volume is going to come out if the city installs a water pump with double the capacity. What you gain by going to the 130-amp generator is the ABILITY to get 130 amps, but only if that becomes necessary. If the vehicle needs 53 amps right now, you could have a 500-amp generator, but it's only going to produce 53 amps.

Where the potential problem comes in is when your mechanic performs a full-load output current test. That is designed to make the generator produce its maximum current for only a few seconds. Related to my previous reply where I discussed a failed diode and getting only one third of the rated current, under this test, you're either going to get very close to the generator's maximum rating, one third of it, or 0 amps. There is no such thing as a "weak" generator that can only deliver some value in between those three values.

To continue with this potential problem, as far back as 1960 when Chrysler first used an alternator, there has been a fusible link in the output wire between the alternator and the battery's positive post. There's two sets of three diodes in every AC generator, and if one in each set were to short, you'd have a direct short to ground, and a melted wire. The fuse link, or fuse link wire, is a short section spliced in that's a smaller gauge, so it's the weak link in the chain. It's insulation is designed to not melt or burn. These fuse devices also protect you if you bump the output terminal with a wrench while it's in contact with the engine. Fuse link wires take some time to burn open, so they won't respond instantly like a regular fuse will. Almost every car was available with a standard generator, or a larger one if it had air conditioning, and an even larger one for police vehicles. The fuse link was sized according to the generator that was installed at the factory. If the car came with a 55-amp generator, the fuse link was probably good for around 65 amps, but remember, you'd never need that much current except during the full-load output test. The problem I'm finally getting to is if you came along and installed a 75-amp generator, it still would deliver only the amount of current the car needed, ... Until someone performed the full-load output test. That is when it would produce 75 amps, and if you did that long enough, the fuse link would melt.

To make matters worse, in almost all vehicles since the early to mid '90s, the fuse link wire has been replaced with a regular fuse that's bolted into the fuse box. Those do not have the time delay feature a fuse link wire has. The instant you start the full-load test, the fuse will blow if the generator is able to develop more than what the circuit was designed for. When the wiring harness is manufactured, the output wire is large enough to handle whichever generator gets installed on that vehicle. Only the fuse link wire is different, per the application. That means if you wanted to switch to a larger generator, you could replace the fuse link wire with a larger one, and the rest of the circuitry could handle it. That isn't always true when the vehicle uses a bolted-in fuse. It's easy enough to bolt in a larger fuse, but there can still be differences in the buss bar under those fuses that connects their common points together. There is always a small amount of resistance in an electrical connection. (Resistance in the water sprinkler analogy would be partially crushing the hose with your foot, which would make water volume go down). Electrical current flowing through resistance generates heat. Heat in an electrical connection tends to increase the resistance, and that generates more heat, ... And pretty soon you're one of the half dozen people who post a photo here each year of a melted area in their fuse box. That happened on its own, but if a generator was installed that had a higher capacity, then add some modification or accessory that needs that additional current, and you have the potential to stress parts of the circuit that can't be upgraded.

Another factor is the car manufacturers have become really good at down-sizing electrical switches and connector terminals to the point they're just good enough, with almost no margin for error. In the '70s, Ford figured out they could save 20 cents per car by leaving off four grease fittings. The suspension and steering parts sometimes lasted long enough to get the car out of the warranty period, then it was the owners' problems. While that sounds like saving a pittance and costing a lot in customer satisfaction, they argued they'd save 20 million cents when they built a million cars, and they were willing to do that for short-term profits. When you ask for a replacement fuse box today at the dealer's parts department, why is it they usually ask for the engine size, generator size, and date of production? It is possible they traced too many garage fires to a melted fuse box, so they beefed them up a little, but only for the larger generators or some other optional equipment. It could be you don't have some optional equipment, and to save a few cents, they left off some terminals in the fuse box. Look in yours and you'll see some empty sockets. Each terminal not installed saves a little money. To say that another way, a smaller terminal might be sufficient for use with the smaller generator, but when you switch to the generator with a higher capacity, and then you add the "hard-of-hearing" stereo systems to play "music" for me, or you add a pile of lights, or even convert a van to a camper package, you risk stressing parts of the electrical system that can't be or weren't upgraded.

Now that you have all this exciting information, it still boils down to your warning message that appears to be related to using the non-original size generator. Since around 2000, Ford's most "intelligent", meaning complicated, computer is the instrument cluster. It is one of two computers involved in blowing the horn, and it sticks its nose into almost every other circuit and system. We don't know what it is looking at to determine when to display the warning message, but when I read the message goes away after switching back to the original generator, it doesn't surprise me too much.

Oh, ... As a footnote of value, a "diode" is a one-way valve for electrical current flow. 1959 and older vehicles all had DC generators which weren't very efficient, but direct current can go right into the battery to be stored. AC generators produce three-phase alternating current that would go rapidly in and out of the battery and generate some serious heat, but nothing would get stored in it. The diodes reroute the pulsing and changing currents to all go in one direction, out to the vehicle and the battery. Those diodes are all "reverse biased", meaning they're blocking current flow, when the engine is off. Those are the only thing stopping the battery from rapidly discharging through the generator when it isn't running. Any one shorted diode of the six reduces the maximum capacity to one third of what it is designed to produce. A shorted diode in each of the two sets results in a rare but major dead short. If you ever run into that, you'll be grateful for the fuse or fuse link wire.

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Friday, May 5th, 2017 AT 4:45 PM

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