Hi, I'm looking to get some diagnosis ideas on a recent issue I've had twice now on my new (to me) 2004 Ford F150 with 127K miles.

Last weekend I was driving around with my family, all of a sudden I notice the engine is running funky...battery light is on! So we head for home...turn off all unnecessary equipment: radio off, lights off, unplug car charger. As soon as the car charger unplugged the battery light immediately turned off. I also noticed at this point the battery gauge went from ~3/4 to slightly over 1/2.

We head for home and make it with no issue. Truck immediately runs better when the battery light is off. I drive by myself for the week to/from work with no issues whatsoever, although I never charge my phone when I'm by myself, the ride is too short for this.

AGAIN today. I take the family out in the car. We're driving nearby, neither of these trips was more than 10 miles from home. I notice that it sounds like some sort of fan is on or something, something does not feel right. I see that the battery light is on again! I had the phone plugged in..we were using it as GPS. So again, we unplug it from the lighter. This time the battery light stayed on a few more seconds and flickered a few times before finally turning off. Made it to our destination and was able to restart the car on the way home.

When we got home I pop the hood and run some tests. When truck is off: 12.5V. When truck turns on: 14.2V. I turn on the radio/high beams/lights: 14.0V. I plug in the phone...wait a few seconds...battery is back up to 14.2V! After I turn off the truck I watch the voltage slowly return to 12.5V solid. This tells me that the battery is OK and that the alternator is most likely OK.

Is it possible that the cars of this age are not made to deal with the load of charging phones?

I'd love to hear some thoughts about this. Thanks in advance!

 

I have never had a truck before, and have only had one for a month now, but I'm starting to see why people who have them love them and do not like anything else!

 

Welcome!

I would get your alternator and battery tested.

Yes, most of us love trucks... that's why I own 2 and might own another one down the line.

 

Like at AutoZone??

 

Buy a new cell phone battery charger (or use a different one).....

Most likely, the one you have is emitting stray RF interference, either radiated that's being picked up by wiring in the vehicle or being conducted back through the wiring system and it's effectively "jamming" the PCM's ability to properly manage the alternator's function.

 

Update: Happened again today. I noticed my fan turned on immediately when I started the car so maybe this is contributing to it? Not the phone charger as it has not been plugged in 2 weeks.

Battery goes up to 3/4 on the gauge, and there is a whirring noise under the hood. Shut the truck off at a light and turned it back on. Went away and did not come back. I am thinking it is the voltage regulator is going. Has anyone had an issue like this before? I'm thinking to change the alternator out but I don't want to do it for no reason.

Thanks in advance.

 

You can pull the alternator and bring it to Autozone and they can test it.