3 Wire Dell Laptop Charger Wire Diagram Site

Most genuine Dell 3-wire chargers use this configuration:

Do not expect your Dell laptop to charge unless all three wires are correctly connected to the corresponding barrel plug pins. Use the resistor tables above if you are building a custom plug, and always verify with a multimeter before applying power to your laptop. 3 Wire Dell Laptop Charger Wire Diagram

When testing with a multimeter, you should see ~19.5V between the inner and outer barrel. You typically will not see a steady voltage on the blue wire, as it is used for data communication. Most genuine Dell 3-wire chargers use this configuration: