Intermittent Charging Problem

[il66pony]

2007 Mountaineer V8 120,000 miles. For a while now, the red charging warning comes on in the message center. If I immediately hit reset, it turns the warning off. Then it may come on again in 15 minutes or not for a day or two. So, I assume it is just a split-second loss of charging. The battery is 2.5 years old, and I cleaned the terminals which were already quite clean. Could this be a false positive?

If not, does it generate a code in the OBD? If so, would it be more specific than just a charging problem? I hesitate to take it to Ford as it might not occur while they have it and charge me a bunch of $$$.

Any thoughts that you can provide on the issue are much appreciated. TIA

Dave

 

[94Eddie]

It could be that your alternator is going bad and is intermittently failing to charge per specifications. Or it could be a bad ground somewhere in the electrical system or a wiring that has the insulation flaking off causing an issue. You can have the battery tested at about any auto parts store. Unfortunately, you could be dealing with a part that is in between operating per spec and completely failed. I had a similar problem as yours with my 2007 Mustang GT that has the same engine as the V8 2006-2010 Explorers and Mountaineers. The alternator finally failed. I replaced it and it works fine now. The alternator is easy to replace and took just 20-30 minutes to do on my Mustang. IMO, electrical problems are the hardest and most frustrating to diagnose.

 

[Bazz270]

Check the alternator regulator pigtail.you can buy one at rockauto etc.
They are pretty common to fail here

 

[il66pony]

It could be that your alternator is going bad and is intermittently failing to charge per specifications. Or it could be a bad ground somewhere in the electrical system. You can have the battery tested at about any auto parts store. Unfortunately, you could be dealing with part that is in between operating per spec and completely failed. I had a similar problem as yours with my 2007 Mustang GT that has the same engine as the 2006-2010 Explorers and Mountaineers. The alternator finally failed. I replaced it and it works fine now. The alternator is easy to replace and took just 20-30 minutes to do on my Mustang. IMO, electrical problems are the hardest and most frustrating to diagnose.

Thanks. I found a thread from a while back where the poster seemed to have the same problem after replacing his alternator. Turned out the pug on the alternator harness was loose. I will check to see if that is clean and tight. Then, maybe buy a new Motorcraft alternator

Check the alternator regulator pigtail.you can buy one at rockauto etc.
They are pretty common to fail here

Thanks for your info. Not sure what the "alternator regulator" pigtail is. is that just the pigtail that plugs into the alternator? Where does the other end plug into?

 

[Bazz270]

Thanks. I found a thread from a while back where the poster seemed to have the same problem after replacing his alternator. Turned out the pug on the alternator harness was loose. I will check to see if that is clean and tight. Then, maybe buy a new Motorcraft alternator

Thanks for your info. Not sure what the "alternator regulator" pigtail is. is that just the pigtail that plugs into the alternator? Where does the other end plug into?

The alternator connector ,plugged to the alternator .part of the alternator harness ( nor the alternator itself) wire goes thru the powertrain module to the instrument cluster indicator