2004 SR5, V6, 2 wheel drive, 125,000 miles in Orlando, FL.

Over a year ago I replaced the factory stereo with a touch screen, Bluetooth, etc system. A short time after, my AC did not turn on (no motor, no fan, nothing). I left the AC in the on position as I drove (light lite) and it turned on a very short time later, with cold air, strong airflow. This didn't happen every time and actually worked fine for a couple months, so I didn't get it looked at. The past 6 months it seems to be doing it more frequently and when I drive over a bump, it turns on. Most recently, it's not turning on and I have to hit a bump harder for it to turn on and sometimes it doesn't. I've noticed lately that it sounds like it's trying to turn on (clicking noise), but doesn't. I feel this is an electrical issues since it started over a year ago and when it does turn on, the air is cold and the air flow is strong.

Any feedback would be greatly appreciated.

Thanks,
Jeff