Just tried starting the truck (Avalanche). It 'acts' 'like the battery is dead. It's not. Fully charged. Put key in, all lights come on like normal, turn ignition and everything immediately dies stone cold. Rinse repeat. Battery terminals look fine. Battery charger gets a big hit when trying to start. Short? I know squat about mechanicals... or electricals for that matter.
Its not a short. A short is a direct connection from power to ground bypassing the load, think taking the long way home vs. short cut. A short would let all the magic smoke out of the wires for that circuit.