Can't get scanner to link up

[fillpot]

Guy's got a 69 Camaro with a trailblazer ls2 and 4l70e, just changed out the camshaft and intake and also put the battery in the trunk at the same time, ok got a few codes so I need to scan it with my snap on scanner and the dam thing want link up, all the grounds seem good and it would log on before I moved the battery, got to get the car retuned and I no if the scanner want log on that my tuners software want for sure any ideas, THANKS!