F250 Super Duty Diesel Question
My pu (2005 F250 SD Diesel w 6.0) would die at an intersection on occations, I took it in to a Ford dealership. They told me the fuel sending unit was bad and so 950.00 was sunk into that repair. ...
Forum Discussion
Brantime wrote:
How do you even "jump" a diesel with two batteries...never needed to try, lol! Ah, for the simple days again with no computers, smog devices...just the simple old power houses that seemed to go forever!!!
Your dual batteries are wired in parallel. Positive to Positive and Negative to Negative. This maintains the 12V but doubles the available amps cranking power.
Your driver side battery is the Primary battery. If jump starting try to connect to this battery - it is most direct to your starter. Connect the same way you would if you only had 1 battery - Positive to Positive and Negative to Negative.
I was told by a mechanic that the PCM requires a certain level of voltage to operate correctly and as batteries age the voltage they are able to provide drops. It seems about 11.5 volts was the cutoff point. Mine (2001) did similar to what you are describing - just wouldn't fire even from a small jump box. Once connected to another running truck about 5 minutes and it fired right up. It was about 6 years old and I replaced both batteries and never again had the problem.
