air does not turn on. i don't think its the control panel in the car. i hit the button to turn the a/c on and i hear a sound under the hood like something turned on but then a few seconds later i hear another sound and it sounds like something shut off and there is no a/c .this has been happening for the last 2 years and sometimes the a/c worked and other days it did not. i always took notice to the sound under the hood . any help in trouble shooting this would be great or any suggestions to what could be wrong would be great as well but i believe its something under the hood as it tries to start but just ends up shutting off. thank you in advance and sorry if this is a repeat question as i did try to search it first before i made a post.