2007 gmc sierra 4wd

[justin goodsell]

Got a problem, the truck goes into reverse and drive, but won't shift to the next gear once I start driving. I've checked all the fuses, replaced both 1-2 & 3-4 shift solenoids,  and changed filter and fluid. Can anyone tell me where to go from here? Trucks broke down 100+ miles away, and I wanna be prepared before making the trip. Thanks

[Iowa Rick]

Had something similar on a ford pickup on the farm. Mice chewed wires going to the transmission. Had to remove intake to get at wires to repair but was cheaper than a new wiring harness. Just a thought