Battery warning light turning on and off.. bad alternator?

[ThorChristian]

Hi all,

2016 Explorer here.

Driving around today and the battery warning light came on. Error message was something to the effect of "check electrical charging system" (can't remember the actual words). The warning came on and turned off 3 times in the 40 minutes of driving.

I just replaced the battery a week ago (the battery was the original, car was completely dead, and never received a battery warning light, so I assumed the battery had just died and replaced it). Car was fine until today, so I am going to guess the alternator is dying/dead?

Two questions.

1) Is there an easy way to check this myself, or based on my new battery purchase, is it safe to assume the alternator is likely bad?

2) if the alternator is dead, will Ford replace my brand new battery also, or is that my tough luck? (FYI, I do have Ford's extended warranty, so the alternator should be covered.)

Thanks

 

[ThorChristian]

Sorry..

Need to add.

I tested the battery and alternator with my multimeter. When the car is sitting in the driveway, not running, I get a reading of approx. 12.20

When I started the car, the reading was 14.66.

I turned on the lights, radio and heater, and the reading moved down a bit, to approx 14.1 or so.

Based on these initial tests, it would seem the alternator is working (at least in my driveway). Could there be another issue to cause that battery light to come on and off?

Thanks

 

[thefranchise713]

Pull for codes before going much further--that light can be illuminated for a few reasons.

 

[xlt03]

Did you do a battery control module reset after installing new battery? If battery was replaced by Ford they would do the reset. If you did it yourself, the car needs to sit untouch (No opening doors, pressing buttons on FOB, door handles or keypad) for 8 hours. If no reset, the module thinks the voltage is low even though you have new battery.

My battery just died without warning. Went into store and came out to start and got the dead battery click-click. Turned off the auto headlight switch and radio and closed the door so no dome light. Pressed start button and it barely started and I went home. Took to dealership since I was still within my 3/36 warranty. They replaced with Motorcraft branded battery with same CCA. Factory battery is branded Ford Motor Company (FoMoCo). Original battery had a bad cell and battery measured 10.4 volts. Many members posted that their factory battery died prematurely. I am guessing factory battery is made cheaply. I wonder how long the Motorcraft replacement will last. The warranty is 100 months prorated after 3 years as sold thru parts department. My understanding eventhough the new battery is 100 months warranty I only get the balance of original 3/36.

 

[ThorChristian]

I did not do a battery control module reset. How do you do this?

When I replaced the battery, i was unable to start the car. I removed the battery and re-installed it, and it then worked. It looked like the car had to re-initialize, and once I let the computer do its thing, I was able to start it and it has been fine for a week.

If I need to remove the battery again and run a module reset, that's fine. I did not see anything in the owner's manual about this, and when I called the Ford dealership, the technician I spoke to had no idea why the car would not start... he never mentioned the module reset.

If you could point me to how to do this, I'd appreciate it.

Thanks

Did you do a battery control module reset after installing new battery? If battery was replaced by Ford they would do the reset. If you did it yourself, the car needs to sit untouch (No opening doors, pressing buttons on FOB, door handles or keypad) for 8 hours. If no reset, the module thinks the voltage is low even though you have new battery.

My battery just died without warning. Went into store and came out to start and got the dead battery click-click. Turned off the auto headlight switch and radio and closed the door so no dome light. Pressed start button and it barely started and I went home. Took to dealership since I was still within my 3/36 warranty. They replaced with Motorcraft branded battery with same CCA. Factory battery is branded Ford Motor Company (FoMoCo). Original battery had a bad cell and battery measured 10.4 volts. Many members posted that their factory battery died prematurely. I am guessing factory battery is made cheaply. I wonder how long the Motorcraft replacement will last. The warranty is 100 months prorated after 3 years as sold thru parts department. My understanding eventhough the new battery is 100 months warranty I only get the balance of original 3/36.

 

[ThorChristian]

I hooked up my code reader, and there were no codes, (except an old P0456 code). Nothing regarding the battery, alternator or charging system.

Pull for codes before going much further--that light can be illuminated for a few reasons.

 

[thefranchise713]

BMS reset can be accomplished with FORScan, or as mentioned, just let the car sit for 8 hours undisturbed. The BMS won't reset (old parameters will remain stored) but the sensor measuring discharge will recalibrate.

That said--I don't think bad BMS parameters will trigger the light. More willing to bet marginal alternator or alternator command isn't matching output.

 

[ThorChristian]

Ok. 2 questions.

1) when you say "let the car sit for 8 hours undisturbed", are you saying I need to disconnect the battery and reconnect it, then let it sit for 8 hours before starting the car again? Or do I disconnect the battery, re-connect it, THEN let it sit for 8 hours undisturbed?

I can certainly do this, but I'm wondering why this problem did not occur right after I replaced the battery? It's been well over a week now and this is the first time the warning light came on. I just started the car an hour ago, and there is no warning light on the dash.

2). If your second comment is true, "More willing to bet marginal alternator or alternator command isn't matching output." what can I do about this? Is this just going to work itself out, or is the alternator beginning to fail, and my multimeter test did not pick it up?

Thanks

BMS reset can be accomplished with FORScan, or as mentioned, just let the car sit for 8 hours undisturbed. The BMS won't reset (old parameters will remain stored) but the sensor measuring discharge will recalibrate.

That said--I don't think bad BMS parameters will trigger the light. More willing to bet marginal alternator or alternator command isn't matching output.

 

[thefranchise713]

Literally, just let it sit, connected. The car will recalibrate. You don't need to do anything.

I'm out of my comfort zone in discussing much more on the alternator--I've just glanced at the code setting criteria a few times, so I'll leave it to the experts on that.

What did you use to pull codes? Generic OBD-II?

 

[ThorChristian]

Yes, I used an Autel OBDII scan tool.

It is sitting now, and will have no activity for 10 hours. There is no warning light on currently, and assuming it starts in the morning, I don't think the warning light will come on... that will not answer the question of what happened, nor will it make me feel confident the problem is resolved. I guess I can keep driving it until when/if it dies, but there should be a reason for this happening.

I found an old thread talking about a similar issue and the remedy was a new harmonic balancer. I have no idea if that could be the issue.

I also recently had a new water pump installed and a new battery cable harness installed. Is it possible that the wire/sensor/connector that throws the error code is loose and is tossing an intermittent code? I don't think this is the case, because there is no stored code... if there was a loose sensor, wouldn't the code remain stored until it was manually cleared?

I will update the board in the morning after I speak with the Ford dealership.

Literally, just let it sit, connected. The car will recalibrate. You don't need to do anything.

I'm out of my comfort zone in discussing much more on the alternator--I've just glanced at the code setting criteria a few times, so I'll leave it to the experts on that.



What did you use to pull codes? Generic OBD-II?

 

[xlt03]

I assume dealership did the water pump job. I never did a water pump on on 5th gen - I assume the alternator has to come out to remove the front cover. If that was the case i would question the connections if they were tightened properly. Also which wire harness was replaced? Would check the connections also.

Keep us posted.

 

[ThorChristian]

Yes, the dealership did the water pump.

The battery terminal wiring harness was replaced. The positive battery terminal was eaten through by a leaking battery. Good times!

I assume dealership did the water pump job. I never did a water pump on on 5th gen - I assume the alternator has to come out to remove the front cover. If that was the case i would question the connections if they were tightened properly. Also which wire harness was replaced? Would check the connections also.

Keep us posted.

 

[thefranchise713]

Did the Autel query the BCM (I presume it's a high enough grade scan tool to hit all modules...) for codes?

xlt03 seems to be on a strong track. BTW, the Autel might be a good enough scan tool to reset the BMS if you want to proceed accordingly--not familiar with the device personally (I reset and work with FORScan), but look for any special functions that can be carried out against the BCM.

 

[ThorChristian]

Just spoke to the local Ford dealership.

Guy said it may be a loose connection, or a sensor inside the alternator that is going bad. Obviously they have to take a look at it... I don't know why a connector that has wiggled loose would show the warning and then clear the warning repeatedly in an approximately 10 minute interval, but I guess it is possible.

I assume it checked the BCM, but I don't know for sure. I don't recall seeing that specifically, however I ran a diagnostic on the entire car and all systems, and nothing came up.

 

[thefranchise713]

Something that might help--are you familar with Engineering Test Mode in the cluster? If you hold down left OK when starting the car (make sure all doors are closed) it'll kick into this diagnostic mode that has a bunch of data. If you roll the down arrow enough--you'll see voltage. Drive around and note when the warning comes up--clear the warning, and take a quick mental note of the voltage at that point and when it clears. Might help the diagnostic track--and it beats driving around with the Autel logging data with cords everywhere!

 

[ThorChristian]

I wish I would have seen your message before I took the car in.

Small update. Went out to start the car this morning to drive it into Ford, and the car did not start. Very similar to the behavior exhibited when I changed the battery. I let the car sit for 30 minutes and came back out and it started right up. No error messages. I tested the battery with the car running and got a reading of 13.2, which was lower than the 14.6 I got last night. Still, the battery had enough juice to crank the car right up, so it isn't drained and the alternator seems to be working...

I'll let the board know what Ford finds out.

 

[peterk9]

When you replace the battery, the vehicle should start right away. If not, and it is intermittent, then there is another issue. Perhaps a bad ground connection on the vehicle itself?

Peter

 

[ThorChristian]

Well, just spoke with Ford. They checked everything out, and found nothing wrong.

No error codes, no loose connections. Battery checked out and so did the alternator.

He said they reset the BCM and said that they have to do this when they replace the battery at the dealership. He said that if a customer replaces the battery, the system should reset itself after 4 start cycles, but they had no way to tell what happened with the battery warning light, since their tech manuals don't give an indication of where to look when this occurs.

I am going to get the car, and I guess I will see where this goes. I'll probably be holding my breath for a while, and hope this was just a software/system glitch.

Should I perhaps call Ford corporate and see what they might be able to tell me?

 

[peterk9]

.....................Should I perhaps call Ford corporate and see what they might be able to tell me?

I recommend driving it a while first before thinking about doing that. I wouldn't think it would be of any use anyway.

Peter

 

[thefranchise713]

Keep the Autel with you for when it happens again, if possible.

This is not the only car that we've read about here recently that would fail to start with some mysterious electrical problem.

I have a weird sense that modules aren't powering up and there's a low voltage (or at least it's being pulled low) situation that's occurring when you have your no-start concern. I have a feeling the Autel is going to have a lot of "I can't find Module X" issues when the no-start occurs.

And I don't trust that the new battery is good, either...