Hi all .I hope someone could give me a pointer on my charging issue.. my 2010 3.0l sport has a annoying charging issue. It only charges on coasting. Unless i unplug and re-plug in the wire to the bcm.. iv replaced the alternator, battery and a new bcm.. once i unplug the wire to the bcm and put it back in i get 14.4v for 26mins ish then it just stops charging unless im coasting down a hill.. soon as i accelerate it stops charging. I confess im no mechanic but every thing i can think of ive done

What is the charge rate when it's not charging?

It is a smart charge system, and will reduce the charge rate to reduce drag on the engine...

12.5v as soon as it stops charging. and after driving for a bout 20 minutes it has dropped to 12.2v. Im using a plug in volt meter in the cigarette lighter socket

Any Charge System Fault warnings on the dash?

No nothing.. no warning lights and no fault codes. If i hadnt put a volt meter on it i wouldnt have known it has a issue until the battery was dead. I went up to my local independent garage to have them re-code the battery in just incase my icarsoft didn’t do it correctly. While I was there it stopped charging so its now booked in for Monday , we spoke about a new firmware update incase it has a glitch in the one it has now..he also mentioned a wire on the alternator that can cause issues. Failing that he said he will definitely find the fault.. just how long it takes and how much it costs me 🙈 hopefully he does find the fault and fix it. When its fixed i will post what i can about the fix on here so i might just help someone else out. Altho he did say this charging problem is very uncommon. I just hope its not a new BCM thats required. Thanks for the replies Mikey i appreciate it

Only a suggestion, but could it be anything to do with the battery management unit on the neg. battery lead playing up in some way..

Cheers
Col

No mate. its had a new earth lead with.. on my 1st post about the problem i put bmc by mistake.. . Cheers

Smart charging system takes it up to 14.4v and then drops back to 13.8v to reduce load and save petrol. Always listen to old people or when they die you will live on in ignorance.
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Learned to 4x4 on 100 mile beach and Frazer Island QLD
Dont spend money on old cars you will never get it back

Thats what i thought should happen. When its fixed stops charging it drops to 12.3v and wont put any charge back in till its coasting .. soon as I accelerate charging stops and it goes straight back to 12.3v