2004 6.6 duramax

I turned truck off one afternoon and let sit overnight. When I started truck the next morning, it ran for a few minutes at idle and shut off. Truck will spin over but won't start up. I changed fuel filter, air filter, and checked all fuses. I swapped fuel relay with running light relay (that was working). I even tried to start with a small amount of starting fluid. Engine has to be jumped with jumper cables now to turn over. Does the two batteries operate seperately, or do they operate together. I'm thinking that one of my batteries may be the problem. I'm going to check that this afternoon. Just wanted to know if anyone else may have had this problem and could direct me in the right direction.

Thanks,
Sidecutter

LLY diesel 2500 and 3500 trucks do not have a fuel lift pump from the factory, and so they do not have a pump relay! The two batteries are connected together to make one BIG 12 volt battery, with lots of cranking amps. It is possible that you have a bad battery-- if one has a bad cell it will drain the other to the lower level. Have them charged and disconnect one of them and test them one at a time.

For the not starting problem-- try bleeding and pumping the primer button.

Sure is nice when people fill out there signature line with the type of truck and mods before they ask a question. Then you may get a better answer and we won't have to GUESS!:cool:

Sounds like you lost fuel prime. Try pumping the primer button until fuel comes out the bleeder screw, tighten the screw and pump till button is hard. Should fire right up.

I would advise against using starting fluid on these engines, its terrible for them. Your glow plugs will make it go BOOM.