Anyone had issues with the check charging light?
- Thread starter jdmans101
- Start date
my chargim system came on too, but it sometimes goes away when i rev. it might be the alternator, the reading from the multimeter is good but not estable. i got my alternator fixed once like 10 months ago so now im looking to buy a new one
joegr
Dedicated LVC Member
Alternator problems that change with RPM are often issues with the brushes or slip-rings.
jdmans101
Well-Known LVC Member
yes I did replace it and haven't had the light come on since, please please make sure you get one from ford, i know its a little expensive but its the only one that works right with this car, dont even consider getting one from auto zone.
Thanks again!
I'm definitely on board with the Ford alternator, having read probably every charging system post on this board going back to 2006.
I'm going to double-check the connections and triple-check the voltages once again, but it's definitely looking like I'm going for the new alternator. The only other thing I can think of is a serpentine belt that is only at the very beginning of being worn out, but your symptoms are basically exactly like mine, so....
Here are my observations regarding my "check charging system" issue.
The message appears only when the engine is started cold, ie after being stopped more than 3 to 3 1/2 hours. It will appear 1 to 4 times per trip. I have observed this primarily during my 25 - 30 minute commute on arterial streets, with 45 mph speed limits. However, last weekend I made two road trips of 1.5 and 2.5 hours one way and it behaved the same
STARTING COLD IN THE MORNING, DRIVING TO WORK
- In hot weather, basically ambient temps over 75 degrees, the messages first appear in the first 1 to 2 miles
- In cooler weather, temps between 65 to 70 degrees, the messages first appear in the first 3 to 7 miles
- The messages never appear after 7 miles
STARTING COLD IN THE EVENING, DRIVING HOME
- In hot weather, messages appear in the first .5 to 1 mile
- In cooler weather, messages appear in the first 1.5 to 3 miles
- The messages never appear after 3 miles
VOLTAGE MEASUREMENTS (measured via DMM at the cigar lighter)
- With the car off, I meaure 12.6 volts
- With the car started, I measure 14.1 volts at all times (idle, or revving to 2500 rpm).
- Voltage is constant with or without accessories loading the system. It's the same when I first start the car, during my commute, and when I arrive at home
- Voltage is always the same, even if the check charging system warning is on or off
RESISTANCE MEASUREMENTS (measured via DMM at the cigar lighter)
- Generally I don't get a resistance measurement, but at times, with the engine running, I measure 12.5 MegaOhms
I've checked the connections at the battery and the rear fuse block, and found no problems. The relevant fuses (alternator and alternator status) are good.
I'm hoping someone like joegr can see some hints to confirm or disprove the working hypothesis that the alternator is in the very early stages of failure.
The message appears only when the engine is started cold, ie after being stopped more than 3 to 3 1/2 hours. It will appear 1 to 4 times per trip. I have observed this primarily during my 25 - 30 minute commute on arterial streets, with 45 mph speed limits. However, last weekend I made two road trips of 1.5 and 2.5 hours one way and it behaved the same
STARTING COLD IN THE MORNING, DRIVING TO WORK
- In hot weather, basically ambient temps over 75 degrees, the messages first appear in the first 1 to 2 miles
- In cooler weather, temps between 65 to 70 degrees, the messages first appear in the first 3 to 7 miles
- The messages never appear after 7 miles
STARTING COLD IN THE EVENING, DRIVING HOME
- In hot weather, messages appear in the first .5 to 1 mile
- In cooler weather, messages appear in the first 1.5 to 3 miles
- The messages never appear after 3 miles
VOLTAGE MEASUREMENTS (measured via DMM at the cigar lighter)
- With the car off, I meaure 12.6 volts
- With the car started, I measure 14.1 volts at all times (idle, or revving to 2500 rpm).
- Voltage is constant with or without accessories loading the system. It's the same when I first start the car, during my commute, and when I arrive at home
- Voltage is always the same, even if the check charging system warning is on or off
RESISTANCE MEASUREMENTS (measured via DMM at the cigar lighter)
- Generally I don't get a resistance measurement, but at times, with the engine running, I measure 12.5 MegaOhms
I've checked the connections at the battery and the rear fuse block, and found no problems. The relevant fuses (alternator and alternator status) are good.
I'm hoping someone like joegr can see some hints to confirm or disprove the working hypothesis that the alternator is in the very early stages of failure.
joegr
Dedicated LVC Member
The check charging system message can be triggered if the PCM detects that the alternator is working (or seems to be working) harder than it should be to maintain voltage, even if the correct voltage is being maintained. (Basically, the PWM power to the rotor field winding is maxing out.)
Resistance measurements across a power source are completely invalid and so the readings that you get are meaningless. There are ways to measure the series resistance of a power source, but this is not how. You are lucky that attempting this didn't damage your meter.
I agree that the alternator is likely headed for failure. It may be worn out brushes as that is the most common reason for failure, but your symptoms aren't completely typical of that.
jdmans101
Well-Known LVC Member
hmm, mine varies when the car is just at idle. Sometimes it will sit at 14 but then it will slowly drop to low 12's or low 13's until I hit the gas and then it will jump back to 14. Wonder if that is normal... also notice that the lights kinda dim when it get low like that until I hit the gas. Just replaced the alt so wonder If I got a bad one.
joegr
Dedicated LVC Member
No, not normal. It should not go below the mid 13's at idle.
If you have a very high power audio system that would explain it, but it would mean that your alternator is undersized for your system.
Thanks, joegr
In the interest of eliminating every variable, I'll add these tidbits and see if they provide any insight:
- This started right after I replaced the driver's seat connector with butt connectors. I disconnected the battery ground terminal before starting, then re-connected it when I was done. The splices are protected by heat shrink and electrical tape (http://www.lincolnvscadillac.com/showthread.php?t=76870 - the airbag light has now been off for two solid weeks)
- My autolamps are not working. The headlights always stay on
- The cigar lighter fuse has blown twice in the last six months. But I think I may have caused the most recent one by shorting across the cigar lighter contacts when testing for voltage. The first one may have been caused by a defective cell-phone charger i was using
I personally don't see how the second and third items could possibly be related, but I'm trying to just check everything off the list. My wife tells me they're "confounding variables."
Well, here's the latest.
The dealership drove the car for a day with a code scanner attached, and are saying the following:
- The voltage regulator in the alternator is malfunctioning. That just confirms what everyone has said in this thread. I will, however, have an independent shop replace this alternator for a couple hundred less than the dealership ($351 vs 550). I will be using a Motorcraft re-man
- The autolamp issue appears to be that the daylight sensor has failed, so it is always indicating that it's night time. They don't guarantee that will fix the issue, but are pretty confident. Go figure, this will cost $300. I'll rant on this one, because they had this car in with the same issue once before and said they couldn't replicate it - even though the headlights hadn't worked in two months. OK, I feel better now.
The dealership drove the car for a day with a code scanner attached, and are saying the following:
- The voltage regulator in the alternator is malfunctioning. That just confirms what everyone has said in this thread. I will, however, have an independent shop replace this alternator for a couple hundred less than the dealership ($351 vs 550). I will be using a Motorcraft re-man
- The autolamp issue appears to be that the daylight sensor has failed, so it is always indicating that it's night time. They don't guarantee that will fix the issue, but are pretty confident. Go figure, this will cost $300. I'll rant on this one, because they had this car in with the same issue once before and said they couldn't replicate it - even though the headlights hadn't worked in two months. OK, I feel better now.
joegr
Dedicated LVC Member
That sensor is easy to replace.
http://deneau.info/ls/s6x~us~en~file=s6xh1019.htm~gen~ref.htm
I'm sure you could get it from Max for a lot less than $300.
Oh, great, man. Now I have to consider DIY. Thanks for nothing!
Do you know how to do these two steps?
"Remove the LH and RH windshield side garnish mouldings.
Remove the instrument panel defroster grille."
I hate the thought of breaking some plastic tab and those mouldings flapping around for all eternity.
scjmc
Dedicated LVC Member
I got the check charging system light intermittant for about a year before total alt failure. If I fold down my rear seat I can see my lightning cap which has a voltage display. Whenever the check charging system message was on the alt was not charging. Replaced with NAPA #1...alt charged but check charging system light remained on all the time. NAPA alt#2 worked great for about 7 months and failed. NAPA Alt #3 worked for about 5 weeks then failed. This one had broken pieces of insulated wire rattling around inside it??? Now 1 week on Motorcraft reman, no problems to report.
joegr
Dedicated LVC Member
Oh, great, man. Now I have to consider DIY. Thanks for nothing!
Do you know how to do these two steps?
"Remove the LH and RH windshield side garnish mouldings.
Remove the instrument panel defroster grille."
I hate the thought of breaking some plastic tab and those mouldings flapping around for all eternity.
I've had plastic parts of the interior break all by themselves, but I've yet to break anything while removing or reinstalling it.
Just pull the front door gaskets off, then pull the A-pillars off. You have to pull pretty hard on them, but it will be okay.
I haven't removed the defroster grille before, but it looks simple enough.
Once the A-pillars are off the defrost grille should pop up. I installed my alarm light where the factory red light is (which is still connected and visible in the defrost vent), which is next to the light sensor. I don't remember how easy it would be to remove/install but getting to it shouldn't be too difficult.
what an abortion... my motorcraft reman had issues when they first installed it. It was fine all summer and now that its cold its acting up again. Revving the engine gets the light to go off, and sometimes stay off. I get all kinds of electrical interference buzzing over my speakers randomly (check charging system light not necessarily on). Off to have them replace it under warranty I guess, as long as it does it when I'm there!
The speaker buzzing sounds like a grounding problem or possibly a loose connection. Maybe it won't have to be replaced. Unless that ground problem is in the alt itself.
So here's the latest:
The alternator was replaced two days go, and so far no charging system errors. If I don't ever mention it again here, you can assume the problem was fixed!
Thanks to all for your feedback on this issue!
I'm waiting for the new light sensor to come in. I gave the side garnish moldings a tug ,and they popped right off. So if the part is something like $50, I'll DIY it. The only reason I'd let the dealership do it is because they'll credit me the $99 diagnostic fee and they paid for a day of car rental ($40) because I told them I'd have them do the work. But if it will really be $300, even if I give them the $40 back and buy the part for $50 I'll be ahead $110.
The alternator was replaced two days go, and so far no charging system errors. If I don't ever mention it again here, you can assume the problem was fixed!
Thanks to all for your feedback on this issue!
I'm waiting for the new light sensor to come in. I gave the side garnish moldings a tug ,and they popped right off. So if the part is something like $50, I'll DIY it. The only reason I'd let the dealership do it is because they'll credit me the $99 diagnostic fee and they paid for a day of car rental ($40) because I told them I'd have them do the work. But if it will really be $300, even if I give them the $40 back and buy the part for $50 I'll be ahead $110.
jdmans101
Well-Known LVC Member
Now that you say that, I had the same problem, I had engine noise coming through my speakers and made the car sound like it was supercharged lol really weird. When I got the new alt put in it stoped.
joegr
Dedicated LVC Member
Bad brushes, probably.
The dealership says that they have to re-program the computer when they replace the light sensor. Does that sound right?
joegr
Dedicated LVC Member
No, it doesn't.
The service manual makes no mention of any calibration needed when changing the sensor.