Water on pass side floor ,not cooliant

[DaveNB1]

Hi all I have a little problem my passenger floor mats are wet after driving on a sunny day with the AC on. I've read somewhere before about condensation coming off the AC and leaking into the car because the drain hole is plugged in the heater box. Can anyone tell me where I can find this drain area so I can check to see if its plugged .


Thanks in advance