2006 XLT charging system

[sky1962]

2006 XLT 4.6L V8, 215,000 miles. I'm getting the "Check Charging System" error message on the instrument panel. Comes on randomly 1-2 times per week, then clears after a couple of minutes. No recent electrical system mods. Took it to the dealer, they plugged in their test rig and couldn't find anything wrong. They stated the tech even did point-to-point testing with a multimeter.
-Can anyone on this forum explain the specific electrical condition that sets the error message? Low alternator output, low battery voltage, ground detected, etc? And why does the error message clear itself?
-Diagnosis from the dealer shop included a P0620 fault code. Research indicates this could be anything from a low alternator output, faulty voltage regulator, faulty/corroded wiring, or a multitude of vehicle electrical problems. Ugh.
Recently replaced the battery. I hate to "Easter Egg" but is the alternator the next likely replacement? Wiring and/or ground faults?
Any suggestions are appreciated!

 

[94Eddie]

The alternator in my 2007 Mustang GT (same as the V8 in the 4th gens) had a slow death that took over a year for me to diagnose. I think the regulator was the problem in that it would work fine for a while and then not for a while. It eventually died completely. You might want to look into replacing the regulator if the bearings are good. Have you checked the voltage at the battery with the engine off and running? You should get 13.7v+ when running and close to 12.6v not running if the battery is fully charged.

 

[SofaKing95]

2006 XLT 4.6L V8, 215,000 miles. I'm getting the "Check Charging System" error message on the instrument panel. Comes on randomly 1-2 times per week, then clears after a couple of minutes. No recent electrical system mods. Took it to the dealer, they plugged in their test rig and couldn't find anything wrong. They stated the tech even did point-to-point testing with a multimeter.
-Can anyone on this forum explain the specific electrical condition that sets the error message? Low alternator output, low battery voltage, ground detected, etc? And why does the error message clear itself?
-Diagnosis from the dealer shop included a P0620 fault code. Research indicates this could be anything from a low alternator output, faulty voltage regulator, faulty/corroded wiring, or a multitude of vehicle electrical problems. Ugh.
Recently replaced the battery. I hate to "Easter Egg" but is the alternator the next likely replacement? Wiring and/or ground faults?
Any suggestions are appreciated!

If you have 215,000 on that alternator it's served you well. I'd replace it and keep it as a spare. Alternators often will give subtle hints before complete failure -- is yours providing a hint? Hard to say.

Ready the parts cannon. BTW, nothing wrong with replacing well used parts proactively.

 

[94Eddie]

Also, I suggest buying a Motorcraft or AC Delco brand alternator.

 

[SofaKing95]

Also, I suggest buying a Motorcraft or AC Delco brand alternator.

Second that....just replaced a "TYP brand" I bought from Amazon back in 2013 for one of my garaged rigs...only put 20,000 miles on it in those 12 years and the bearings started to go -- maybe they dried out. Regardless, I've got 30+ year old Delco's with 100,000+ miles and still going strong. Also, another case in point is if the OP's 215,000 is on a Motorcraft original, 'nuff said.