diagram's for a 96 cummins?
 

im having some problems with my new 12v i dont know much about the 12vs at all, bought the truck cause they couldnt get it running and thought it was a bad fuel line. i plugged the filler neck and stuffed a air chuck in it and found a leak. its where the lines first meet the motor so im looking for a diagrams so i can kind of trace it all down thanks

It goes from the fuel tank to the fuel pump then to the fuel heater then to the fuel filter then out the fuel filter into the injection pump. The fuel pump and fuel heater might be switched in order, can't remember. Anyways, that is the supply of fuel. The return flow goes from the front of the injection pump straight back to the tank. The return lines on the injectors actually go back to the fuel filter so if they are letting air in, they are dumping it right into the supply side of things.