The Mustang Forum for Track & Racing Enthusiasts

Taking your Mustang to an open track/HPDE event for the first time? Do you race competitively? This forum is for you! Log in to remove most ads.

  • Welcome to the Ford Mustang forum built for owners of the Mustang GT350, BOSS 302, GT500, and all other S550, S197, SN95, Fox Body and older Mustangs set up for open track days, road racing, and/or autocross. Join our forum, interact with others, share your build, and help us strengthen this community!

Gt350 charging problem… need help

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Hello!
I have a 2018 gt350 with 20k mi
So I got a charging system service now error, battery won’t charge, so I replaced it. Then the voltage won’t go above 14 v and drop to 13 when throttle hard. So I replaced alternator
After reset bms, voltage is constant between 13.9 and 14.1 but I still got two codes p065b p0626
Error will go away when throttle hard
Help needed… thanks

34433AF7-7800-4B41-994B-8F393FE728C5.png

F5581FD8-687C-43C1-AA82-2148B48C4602.png
 
Not sure if this would have anything to do with your situation but have you tried disconnecting the charging sensors or whatever they call them? The rings around the battery cables, they monitor current for smart charging. Removing them tricks the system to run the alternator at 100% and not allow it to throttle back.
 
Not sure if this would have anything to do with your situation but have you tried disconnecting the charging sensors or whatever they call them? The rings around the battery cables, they monitor current for smart charging. Removing them tricks the system to run the alternator at 100% and not allow it to throttle back.
I thought they both were battery temperature sensors? That’s what I read from diagram Lol I could be wrong
 
I’ve not looked at them on the diagram, rather seen a few threads on other sites of people with charging problems removing them and getting a constant 14+V. A few people followed up saying that they’ve done so for years without issues but of course there could be a risk so YMMV.
 
1,249
1,243
In the V6L
Hello!
I have a 2018 gt350 with 20k mi
So I got a charging system service now error, battery won’t charge, so I replaced it. Then the voltage won’t go above 14 v and drop to 13 when throttle hard. So I replaced alternator
After reset bms, voltage is constant between 13.9 and 14.1 but I still got two codes p065b p0626
Error will go away when throttle hard
Help needed… thanks

View attachment 68700

View attachment 68701
I had the same gong-show and screen display - "Service Charging System" messages. Swapped in a new battery, things went quiet for a while, then it came back. At the dealer's now getting a new alternator.
 

TMO Supporting Vendors

Latest posts

Buy TMO Apparel

Buy TMO Apparel
Top