A device for preventing electrical shorting between positive and negative terminals of a wiring harness includes a clip securable to conductors of the harness, a wall extending from the clip to be positioned between first and second terminals of the conductors when the clip, and a shield attached to the clip and movable between a first position wherein it blocks contact between a tool and the first terminal while allowing contact between the tool and the second terminal, and a second position wherein it blocks contact between the tool and the second terminal while allowing contact between the tool and the first terminal.