Just changed both batteries in my 2010 F-250 6.4L diesel and after i replaced the first I had power, when I replaced the second, now i have no power. both batteries where charged.
Did you connect them right. Make sure the polarity is correct.
Yes. talking to the service dept at Ford I blew a fuse because I didn't connect them all a once I disconnected the second Battery in series so I had enough room to get the battery out and when I reconnected it after I connected the first one I blew a fuse.
Glad you found the problem
Looking for a Used F-250 Super Duty in your area?
CarGurus has 45,058 nationwide F-250 Super Duty listings starting at $2,000.
Search Ford F-250 Super Duty Questions
Ford F-250 Super Duty Experts