Build a Keyless Unlocker

Time: 2 Hours Cost: $65.02 Difficulty:Relatively Easy

  1. Open the printer. Slide the battery cover plate off and remove the battery. Snap the plastic bezel off the front of the printer, and remove the two screws that hold the cover plate in place. Remove the narrow ribbon cable.
  2. Route two wires into the printer via the paper exit slot. Solder one to the “TP14” solder connection point on the circuit board, and the other to any ground point on the board.
  3. Reassemble the printer. Slide the two wires through the paper exit slot. Solder the other ends of those two wires to each one of the coil prongs on the relay. Solder two different wires to the remaining switch prongs of the relay.
  4. Open the key fob and locate the button that unlocks the doors. Solder one relay wire to each pole of the switch. Reassemble the fob. Connect the printer’s power supply to an inverter, and plug it into your lighter.
  5. Turn on the printer. Enter passcode 6000 to pair your phone with the printer. Send a photo via Bluetooth, and the relay will trigger the key fob to unlock your car’s doors.