Check Charging System until Engine Running

[ChillTheNerd]

Hello.

 

Working on my wife's 2012 Ford Edge SEL AWD (w/ all factory options).  No aftermarket modifications at all. 

 

Two days ago (Aprils fools, naturally) she got an intermittent "Check Charging System" warning while idling at stop lights, parking lots, etc. on her way home.

Opened it up and one of the first things I noticed was the battery terminals were extremely loose.  New batter was installed 31 Dec 2021, so it's 93 days old now. They must have failed to tighten it up. 

I scanned the engine with 

 

I fully disconnected the battery earlier today for 30-45 minutes, then re-connected and tightened it down properly.  When I start the engine, the voltage is ~12.4 until a brief rev, and the voltage settles at ~14.4-14.5.

Here's a video the voltmeter connected directly to the battery when I started and then revved it:  https://youtu.be/cYw4kwGndk4

 

After I took this video, I turned the car on (engine not running) and got the Check Charging System warning.  Without removing the key, I turned the engine over and the warning immediately went away. I turned on every electrical system I could while the car was idling there - high beams, AC (fan), blower, seat heaters, interior lights, rolled windows up/down and held the brake.  Voltage holds strong above 14. 

I suspect the vehicle BMS still needs to adjust after I tightened the battery leads. 

 

But does anyone have thoughts? 

 

If it does reset or the issue goes away by the morning I'll update here.

[enigma-2]

BMS reset,

engine on ,not running

Flash brights 5x

Step on brake pedal 3x

Wait several seconds

Battery light will flash 3x indicating reset

[ChillTheNerd]

So following up here:

 

BLUF: I changed the alternator and the issue is resolved. 

 

After my original post, I let the vehicle sit for 8+ hours and the problem didn't come up again for several days. But it did present eventually. We were actually on the road pretty far from town, and after a fill up, I turned the car on and got the warning.  Tried revving it to get past it as before, but no luck.  Checked the battery voltage and it was steadily dropping despite any RPM changes (especially with electrical systems running).  I shut it off about 5-10 mins while deciding what to do (again, far from home),  turned it on again, revved it, and got 14.5 volts again... Since we had a full tank (and 190 miles to go), I didn't shut it down again until I got us where we were going,  dropped the wife off,  picked up a Duralast Gold alternator and went to my friend's house in town to do the swap.  I didn't know for sure if that would fix it, and I DEFINITELY wanted an OEM part,  but I needed to try and OEM wasn't available on my time line,  so faith in Duralast it was.  4 hours later we had the Edge back together and haven't had any issues since.  Voltage is steady at 14.7 now upon startup and we're well over 1k miles since (currently still on the way home). 

 

The original alternator terminals were severely corroded which I couldn't really see until we removed it, and the corrosion seemed to go "deep". 

 

We basically did everything in the video linked below (which I'm sure many here have already seen).  One observation though is that loosening the belt wasn't as easy as we thought.  There's very little room to get a tool in there, so we used a crowbar and a large impact socket to offset it from the engine mount for leverage. I pried it back while my buddy pulled the belt off / put a new one back on. 

 

 

[WWWPerfA_ZN0W]

well done, enjoy!