heater making loud clicking
 

i have a 01 t&c 3.8 limited and its been rather cold lately and the heater normally takes like 15 minutes to work reasonable the engine has to have been on for a while so i have thought there might be a problem but since i live in cali wasnt a concern however yesterday i turned the heater on and there was a lound clicking like noise that was coming from the outside of the car sounded like engine carpartmment on the drivers side was wondering if anyone had heard of anything like this or any suggestions thanks for your time