I made a post a few weeks ago, never got any help. Hoping someone responds to this one. Truck is nnbs 07.5 gmc sierra, came with 4l60 5.3 combo. Now has 6.0 4l80. Wasnt moving before,got tcm and ecu redone, runs and moves great. I had an issue before where my front blinkers wouldn't flash. They light up, but won't flash. Now my issues ( since its driveable ) are that the radio fuse keeps blowing. It is a factory deck, wiring, etc. & it will start great when cold, no resistance, quick cranking,etc. When it is warm (sometimes.. not all the time ) it gets a struggle cranking,like a dead battery but its not. Doesn't seem to get fuel either when it does this and I have to pedal it to start. When it finally starts, the tach doesnt work and it wants to die. Ive checked all grounds, all fuses, battery was tested even tho its brand new, ecu and tcm were rechecked, no ideas. Ive been told onstar can have something to do with it, along with ignition, or even a bad starter robbing power and ground from other areas of the vehicle as well as a bad battery ground. Looking for anyone to bounce ideas off of, need desperate help. I have an event this truck is supposed to be at in less than 2 weeks. Any help would be appreciated.