Ford Powerstroke Diesel Forum

Ford Powerstroke Diesel Forum (
-   6.7 Electronics Discussion (2011-2016) (
-   -   Battery Light On (

SouthWestPiling 02-24-2017 12:43 PM

Battery Light On
I have a 2012 6.7 at 50,000 miles with the single heavy duty alternator.. Noticed the battery light illuminated on my instrument cluster yesterday. Checked the batteries and got 12.6 v with the engine off and 13.7 volts with the engine running. Batteries are 2 year old Napa Legends and tested 12.6 v each when I disconnected them, so they seem to be okay... (I haven't had them load tested yet though) Checked for loose or faulty connections with no visible signs from the alternator to the battery, and ground connections seem okay as well.

It's not throwing any codes just the battery light after about 20-30 seconds after start up, has anyone experienced this and have any suggestions by chance?

Thanks !


2016 Magnetic F250 02-24-2017 03:02 PM

I would try and scan it and get the code if you can and see what it says. I would start from there.

Sent from my SAMSUNG-SM-N910A using Tapatalk

SouthWestPiling 02-24-2017 03:32 PM

Thanks, I'll give that a shot again in the morning but when I scanned it earlier today I wasn't getting any codes come up with my scan tool.

SouthWestPiling 02-25-2017 11:10 AM

Well to follow up, I had the batteries load tested and they came back fine with over 800 CCA but just slightly undercharged, so gave them a quick charge and threw them back in the truck. Truck starts no problem but the battery light did come back on. So my code reader just pulled a P068A - Powertrain and I found online the P068A is "Power Relay de-energized too early"

Any ideas what this might be? Could it just be a bad connection at the pcm/ecm or is it leaning toward a new pcm? I'm a little confused at this point and leaning towards taking it to the dealer... :(

kaya 02-25-2017 11:19 AM

Everytime I've had a p068a, it was caused by at least one bad battery. Have seen this code several times.
Check all connections. Particularly at the passenger side battery and junction box next to battery.
You will need to monitor the vbatt PID using a scan tool to start

SouthWestPiling 02-25-2017 01:42 PM

Thanks kaya I did triple check all the connections and no luck but I seemed to clear the P068a code for now, still have the battery light on the dash come on after start up though. On a few other posts most people say new batteries solved similar issues even if the batteries tested ok.. so I'm leaning toward new batteries although I didn't think that would clear the battery light on the dash.

JRTJH 06-28-2017 04:08 PM

Just wondering if there's any followup on this battery light? Over the weekend I also had the battery light come on about 15 seconds after startup. Battery voltage was 12.62V, dropped to 12.52 volts after about 5 minutes of idling. I took it to Ford (still in warranty) and they said it was a "bad connection under the motor". I couldn't discuss it with the mechanic (service writer seemed to only relay what was on the paperwork, so I don't know "the rest of the story".... I did let them know that I've had to clean corrosion from the passenger side battery negative terminal 4 or 5 times since the truck was new, so they also replaced that one battery. I asked about replacing batteries that are "in a pair" as a pair. Ford won't approve that per the service writer, so I've got one new battery and one 2 year old battery. Hopefully I won't start the "battery flip flop" failures.... Anyway, just wondering if SouthWestPiling ever solved his problem......

msk182 07-12-2017 10:50 AM

I had my battery light come on and I went through the whole gambit of checks. Finally ended up taking it to the dealer where they had it for a few days to chase down a bad wire - the one that controls the indicator light on the dash. Everything was working perfectly, just that wire was bad.

Dibbles6.7 06-12-2018 08:01 AM

I am having the same issue on my 2011 f250. put new battery's and an alternator on mine and the light is still on. I have read that it's the wire that runs from the alternator down under the motor I believe and to the pcm or ecm. I guess they have a spot that corrodes? Has anyone else heard of this? I am not real crazy about trying to chase this down with as many wires as there are on these things.

Kyler44 08-31-2018 08:15 PM

Yes I have the same problem, it’s either the yellow wire or the red wire that goes from the alternator to the computer... anyone know what wire it is?

natetp1227 09-27-2018 01:45 PM

I had the same issue about a month ago. Battery light came on, I monitored with voltage with SCT tuner. Took it to my buddies shop he load tested and checked the alternator, no problems. Next day drove about 15 miles and all my gauges and radio unit went crazy, voltage dropped down to 11. My buddy replaced the alternator. I drove it about 50 miles and the battery light came back on and headlights flickered and voltage dropped to 12. Took it back to my buddies shop, and they took it to an electrical shop and they replaced the above mentioned faulty wire. Light gone! Driving a few days later lights still flickered when voltage dropped below 14. Replaced alternator again and all is well. Now I am having an issue with my radio/infotainment system turning itself off and clock not working. ???????

Paid about $400 to have wire replaced.

ATCguy 01-09-2019 02:56 PM

1 Attachment(s)
Well, my turn for the subject issue...

Light first noticed about a week ago during a 20 mile trip. Arrived destination, completed a few tasks, restarted the truck about 45 mins later, no light on the return trip. Figured it was just a hiccup in the system. Then day before yesterday, the light came back on as I was finishing a drive back home for the day. Started the truck the next day... no light when the engine started, but as soon as I put it in gear, the light returned. :(

Called the local shop, who agreed to try to fit me in during the late afternoon yesterday. Drove over, and the tech went to work. After about 2 hours, came in shaking his head. Said both batteries tested good, as did both alternators. Good voltage out of the alts, and good voltage into the batts. Tested the big fuse block on the firewall, stated that was good as well. Reported seeing a different code than in post #4 above. My code was P-0620, which is “Alternator control circuit – malfunction”. He determined issue had to be something between the PCM & connectors... possibly a chafed wire, possibly a bad connector, or even PCM going bad. Unfortunately, closing time was approaching... and to determine what would require me bringing the truck back in a leaving it next week when they could schedule me on the calendar, as this would take a couple of hours of labor to handle the issue. He also provided me a schematic showing where he theorizes the problem may be... which I've included in the attached file.

So, since the truck starts up fine each time, and otherwise seems to run ok (except I have noticed it seems to be idling higher than normal)... I figure I;'m good to go until they can get me back in the shop next Wednesday, and we'll see how it goes. I've bookmarked this thread and will show it to them when I return... maybe it'll help speed things along.

Will come back to update then...

midipuppies 08-10-2019 01:31 PM

Any news on this?


All times are GMT -8. The time now is 11:32 PM.

Powered by vBulletin® Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.

User Alert System provided by Advanced User Tagging (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.

For the best viewing experience please update your browser to Google Chrome