For older reader kits that don't have the mating plug, you will need to splice to the wires.
Start Wires:
The two red output wires of the High Voltage relay should be connected to pins 5 and 6 on connector X21 on the machine's control board. There should be an existing wire harness connecting X21 to an empty connector X121. Simply splice the relay's output wires to these two wires. This is shown below:
High Voltage Sensor wires:
It is CRITICAL that the high-voltage sensor, which senses the door open/close state, be installed correctly. Otherwise, if the door is open, the reader will still take money from the card and the vend will NOT be registered with the machine. The connection varies between Gen5, and Gen6Gen 6 modelsSplice the two High Voltage sensor wires across wires on pins 2 and 4 on connector X30.