I have a 2005 Chevy Silverado 1500 classic crew cab 5.3 4x4, I recently put a transmission, the same transmission model in this truck after putting the transmission in I started it up and it had no throttle response, found that somehow both the pedal, tac and throttle body were bad, I replaced all 3 and I still have no throttle, everythings plugged in, all around, didn't pinch any wires putting the trans in.

What I've done to test so far, made sure the grounds were good, checked wiring, found that the alternator was overcharging by 18.80 figured out tac has a failsafe, disconnected alternator, hooked jumper cables to the battery and tried the truck like that, still no throttle response.