So i just purchased an 04 2500 5.9 cummins 4x4 6 speed last Tuesday. Drove it around and started fine Wednesday and Thursday. Left for the weekend came back Sunday. Went to drive it Monday night and wouldnt start. Figured the batteries were dead somehow, no biggie hooked up a charger and put on start mode which is a 250 amp starting mode. Enough power to start a dead semi at work. I climbed in waited for the plugs and tried to start it. Barley would crank over. Tap the starter thinking that could be it. Same result cranked over twice. I then shut off the charger pulled and checked fuses with a voltage meter they all tested good. Then decided to check my batteries to see if they were even down in the first place. Both batteries read 12.5 volts, while the hood was up i noticed it had a reprogrammed ecu in 07. I dont know but think that could have something to do with it. I have power under the hood but no power in the cab. And with the key out the dome light and panel lights flicker on then off and a beeping sound. Does anyone have any clues what is wrong or if its something that can be fixed by a do it yourselfer.