Ensure the fine strands of the ID wire do not touch the positive or ground wires, as this can permanently damage the laptop's charging circuit. DELL Laptop Charger Pin-Out Explained (For DIY Mods)

Black, or an uninsulated braided outer wire shield.

wire is broken, the laptop will often display a "Power Adapter Not Recognized" message. It may still power the laptop, but it will usually refuse to charge the battery.

ID pin will permanently destroy the laptop's motherboard charging circuit. Slide the large outer heat shrink over the entire assembly and secure it tightly. Safety and Troubleshooting

Dell's standard round barrel connectors (like the 7.4mm or 4.5mm sizes) distribute these wires as follows: Wire Color (Typical) Outer Barrel Negative / Ground Inner Barrel Wall Positive (+19.5V) Center Needle Pin Charger ID / Signal Blue (or Green) Why the Third Wire Matters Blue ID wire