Charging System: Service Now

[Jimbo7]

Pictures of said wire would be helpful

Yeah, I know. It's dark. It's snowing. Maybe in a couple of days. If you just look between the negative and positive terminals you'll see that the wire and the connector are pretty easy to see. You'll find it in 30 seconds now that you know where to look.

Sponsored

 

[5thranger]

Guys, I've figured this out. This happened to both my and my neighbors 2021 Ranger. Kept getting an intermittent light. No rhyme or reason as to how and when. Once it came on, it stayed on until I turned it off. Restart and it's no longer on. Drive 3 miles and it's back on. Dealer says that it's the alternator and they'll replace it for $1300.00. Truck is 2500 miles out of warranty. Something didn't add up. I got my multimeter and my alternator was putting out a healthy 14.9 volts. Turned the AC on full and the brights on. Dropped to 14.8. Battery at rest was 13.6V, so we know that the alternator is fully charging the battery. So, I looked on YouTube, found the same stuff that you probably did. 225 amp alternator fuse and another fuse as well. They were perfect. In digging around I found a crappy wire, about the gauge of an old landline telephone wire going to the underside of the positive battery terminal. With a cheesy plastic white connector like something on a $15.00 RC toy. I wiggled it, it was loose, pushed it up and drove it. Light never came on. Came home, wrapped the wire and the connector with electrical tape and haven't had a problem in 1500 miles. Neighbor had the same issue. Took it to the dealer and the tech told him that he had the same truck with the same problem and he replaced the alternator and it fixed it. I wrapped his little wire and no problem any longer. Guys, they know that it's the connector that goes to the sensor that gives you the light. They want to sell you an alternator replacement. Follow the alternator cable to the terminal, make sure it's a tight connection. Then, find the crappy wire that runs under or near the 225 fuse. Wiggle that, push in the connector and drive it. If the light doesn't come on, wrap it with electrical tape. It's not your alternator, it's not your battery. It's the crappy sensor connector. They don't call them Stealerships for nothing. Hope this helps.

The dealerships will tell you it's the alternator after they have replaced it, and it wasn't the problem. Irritating as hell.

 

[Jimbo7]

The dealerships will tell you it's the alternator after they have replaced it, and it wasn't the problem. Irritating as hell.

You're right. They'll replace your alternator that doesn't need replacing and fix the wire that they know was really the problem. Everything is fine now, you're out $1300.00 over a $20.00 fix and you think it was the alternator. To those that don't have a multimeter or the ability to test your battery and alternator at home, do this; Take your truck to a combination of 3 or more Autozones, O'Reilly's and your local tire shop that also does mechanic work. They'll test your battery and alternator in less than 3 minutes. If they all tell you that your battery is good and your alternator is good, you know the problem is elsewhere. The little wire that runs to the bottom of the terminal comes out of a harness near the bottom front of the battery. It's easy to find, just follow it about 8 inches to the connector at the bottom of the terminal extension. That connector goes to the sensor light. Let me know if that helped you.

 

[airline tech]

It's been mentioned before to check (wire check) for power, but no one has stated they found an issue with it yet.

The wire in question is (Item B) Not pictured (Mounted just below the B) on the side of the battery. It is a single wire connector that taps the BMFL for (+) input to the BMS sensor.
It's just a short run over to the BMS sensor, this is one of the items on the list that can produce that message.

So, with the alternator proven to be producing the correct voltage, the BMS sensor lost an input thus it is now transmitting a data loss on the LIN circuit to the BCM.
Actually, the manuals state if there if a fault with the BMS sensor or the LIN circuit the PCM will trigger the alternator into a (Failsafe) mode and only produce a 13.7-volt output (approx) Max.
That is why - I always ask the question (what the alternator is producing (Output)

I know the question is coming - and I think the reason why the same message does not show when you disconnect the sensor is that you are fully disconnected (disabled) and thus no transmission of data on the LIN bus to the BCM.
So basically, by disconnecting the connector you are stopping the (LIN) data transmission and using Forscan to disable is basically turning off the BCM (LIN) Bus circuit


Easy to check that wire - just disconnect the BMS sensor connector and Probe the pin for power.

 

[Jimbo7]

"
It's been mentioned before to check (wire check) for power, but no one has stated they found an issue with it yet.

The wire in question is (Item B) Not pictured (Mounted just below the B) on the side of the battery. It is a single wire connector that taps the BMFL for (+) input to the BMS sensor. "


What?? My entire post was about the cheesy connector on that wire. THAT'"S the issue.

 

[airline tech]

"
It's been mentioned before to check (wire check) for power, but no one has stated they found an issue with it yet.

The wire in question is (Item B) Not pictured (Mounted just below the B) on the side of the battery. It is a single wire connector that taps the BMFL for (+) input to the BMS sensor. "


What?? My entire post was about the cheesy connector on that wire. THAT'"S the issue.

The title of the post - Check Charging Sys (Message)
The cheesy connector (you found) - GOOD FIND - BTW
Feeds as an input to the BMS sensor on the negative terminal - it is the input ref for (+) voltage.

The BMS sensor itself is sending information to the BCM (Via a LIN circuit bus) various members have had that message come up and one of the (Test) procedures for that message is to check the BMS sensor connector for (+) power (The other end of the wire you are referencing) if the connector is not secure (which you found) then the BMS sensor is not seeing a (+) voltage input.
This (bad connection) just one of the possibilities that can cause the (Check Charging Sys) message.

So, for previous owners, it has been mentioned to - Check the BMS connector for a voltage input, none until NOW have found an issue or have reported an issue.
So, GOOD FIND and now there is another - CHECK THIS Connector to add to the list of highly probable causes for the message.
Note: A high number of reports for this message come just after a battery replacement, so this makes sense as you are disturbing that connector in this process and with it being somewhat hidden (not on top) and easily seen it can be very easy to pull up the BMFL and put stress on the connector (thus damaging its ability) to securely lock in place.

My side note for the BMS sensor is that some owners disconnect that connector to disable the ASS and or the BMS systems. They are disconnecting without any - Check Charging Sys messages.

 

[Jimbo7]

The title of the post - Check Charging Sys (Message)
The cheesy connector (you found) - GOOD FIND - BTW
Feeds as an input to the BMS sensor on the negative terminal - it is the input ref for (+) voltage.

The BMS sensor itself is sending information to the BCM (Via a LIN circuit bus) various members have had that message come up and one of the (Test) procedures for that message is to check the BMS sensor connector for (+) power (The other end of the wire you are referencing) if the connector is not secure (which you found) then the BMS sensor is not seeing a (+) voltage input.
This (bad connection) just one of the possibilities that can cause the (Check Charging Sys) message.

So, for previous owners, it has been mentioned to - Check the BMS connector for a voltage input, none until NOW have found an issue or have reported an issue.
So, GOOD FIND and now there is another - CHECK THIS Connector to add to the list of highly probable causes for the message.
Note: A high number of reports for this message come just after a battery replacement, so this makes sense as you are disturbing that connector in this process and with it being somewhat hidden (not on top) and easily seen it can be very easy to pull up the BMFL and put stress on the connector (thus damaging its ability) to securely lock in place.

My side note for the BMS sensor is that some owners disconnect that connector to disable the ASS and or the BMS systems. They are disconnecting without any - Check Charging Sys messages.

You are correct. I just explained it in a way that that non- mechanic/techs can understand. The sad part is that the Ford techs know that this is the issue and still tell customers that they need a new alternators.

 

[got3fords]

The sad part is that the Ford techs know that this is the issue and still tell customers that they need a new alternators.

Really not sure I am buying that this is common among dealers. I can understand they change out the alternator not knowing any better, but to purposely defraud the customer that often? I dunno...

 

[Jimbo7]

Really not sure I am buying that this is common among dealers. I can understand they change out the alternator not knowing any better, but to purposely defraud the customer that often? I dunno...

Awww. Bless your heart.

Sponsored