About 3 months ago, the check charging system indicator illuminated on my 2004 F-150 and then a few minutes later I was broken down on the side of the road. I took it to the dealer, and their diagnosis was that I needed a new battery and alternator. I approved the repair and everything seemed to be resolved. However, when I drove home the check charging system indicator warning came on again after the repair work.

I took the truck back to the dealer, so that they could do more diagnostic work. They decided to try another alternator and after they drove it around a while the check charging system warning came on again. Then, they replaced the alternator a third time and did some data log captures to send to Ford for further troubleshooting. Eventually, after them driving it around for a week they determined that after a while the code cleared from the computer and everything was ok.

I was skeptical at this point, but sure enough I drove it home and everything seemed ok. The check charging system indicator has not come on again until a few days ago (so this has been about a 3 month span). On my way to work, the check charging system indicator came on for about 30 seconds and then went off. Then, the next day the check charging system indicator illuminated for about 15 seconds and then went off. It has not happened since (about 3 days), but I am nervous that I am going to break down on the side of the road again. It seems intermittent and I am wondering if there is a bad wire in a harness somewhere. I have the Haynes Repair Manual and have been trying to diagnose it, but with it so intermittent I am not sure how to approach it.

Any thoughts or ideas on what to check for? I am open to replacing the wiring from the battery to the alternator or some other wiring harness... but I just don't know what is best.

 

first thing i would check is your grounds.. clean/tight/free of corrosion...

 

I am in the process of checking all of the grounds. I was able to take a picture the last time it occurred and you can actually see the battery gauge shows a high reading.

Something is very strange and I am just trying to think of next steps to trace it down. If there are any other diagnostic steps anybody can think of that I can check, please reply.

 

 

Click these & read the captions:


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Have same isues with check charging system light on my 09 f-150 shows no signs of weak battery or charging system starts an drives fine auto store checked system says charging just fine just the message pops up at first thought was due to bad connection at positive post as terminal was extremely lose an unable to tighten up so I replaced it message went away for about 3 hrs lol but as said everything checks out just seems to be glitch with light

 

That post is about 5 years old, glad you got it resolved.