Car power is very low while airconditioning is on

Car acceleration is very good once car is taken up after D drive. When a/c put on, great drag felt and car is like not moving. If car is going in 60 speed and a/c puts to on, the speed gets almost stagnant. When a/c is on and car is stopped due to any reason, its very hard to pick it up again and a/c is to put off and then car accelerates.

I have got my a/c checked for any problem. Its compressor bearing was having some problem and same was replaced. However, even then, its hard to pick the vehicle with a/c on.

Car engine and auto transmission is checked by certified mechanic and all goes ok without a/c. But airconditiioning is killing car pick and acceleration. Dear I need some checks recommended by you in order to isolate the problem.

Waiting for your positive response