2008 Honda City Dragging Car

Hi! I have an automatic honda city car 2008 model. My problem occurs usually while i'm on a traffic with my gear on the D. Whenever the a/c or the compressor starts to function, my car drags like i've been hit by a car on the rear. What I did is that I turned off the a/c, but then, it did happen again until I noticed that the cause is when the radiator fan starts to function. To be sure, I switch off the aircon and I pull out the wiring on the radiator fan. When I drove my car, it runs smoothly. Does my car have a voltage regulator or something? Do you think the idle control or air regulator have something to do about it? Tnx and hoping for your reply soon!