The additional power puzzle is a puzzle in Obduction that sends electricity to areas not already powered by the power generator puzzle. The third minecart objective (whereby the fake pile of rocks in the Arai compound is destroyed) must be completed first. It grants access to the Scrapyard and the Garage, letting the player use the cash register, a vital part of the Tower entry puzzle. It consists of two main parts.
Go to the Junkyard (the upper collection of junk). Find the yellowish orange backhoe shovel on the side facing the river. Step inside the shovel, push the button, and you will descend into the Scrapyard.
Walk down to the ground, turn left, and walk forward until you encounter a humming power box on your right. Open the box, and move the left switch up. Power is now restored to the Garage and Downtown Hunrath.