Car clicking when ac on and cruising

When I am driving and cruising at around 50-70 mph, and when my A/C is on, my car will make a sound like a click or a pressure sound and will kind of jerk a little bit. I have already spent 200 dollars to get it fixed and it is still not working. He has changed all the plugs and wires, changed the A/C switch. What could this be. It is killing me financially.

ok 1. check the ac compressor, i dont think thats what it is though.

2. i believe all of us have this same problem. ill be cruising with my windows down and get hot then rolll em up and hit the ac. my car kind of pulls back and doesnt drive as fast- reason: it takes hp to run the a/c (not sure about cruise or not) but you said you have a 2003 so your prolly pushin between 140-150 hp and when you flcik on your ac your getting roughly 130-140. that explains the drag. the sound could be your alternator or your ac compressor like said. safest thing take it to a shop to recharge the freon prolly cost no more then 35-50 bucks.

also something else if your tired of the drag with your ac on. just buy a performance pulley. itll put the hp back and you wont even know when ac is running.

also 200 dollars is not alot to fix a car. id rather spend 500-600 dollars to fix my car then have to buy a new one