Hello, I replied on this issue to another topic on this forum from the past and then I copied & paste it on here.
Hello,
I don't own a Ford Fusion but have a 2008 Ford Escape 2.3 Duratec engine. My Idler Pulley broke once. I pointed the problem to my Ford Escape's Power Steering Pump. This is the scenario...you see, I have the "habit" of when I start my Ford Escape I have my left hand on the Steering Wheel. Upon START UP (especially COLD START UP), accidental wiggling of my left hand on the steering wheel causes the Idler Pulley to be pulled by Power Steering Pump. Now, I start my Escape without my left hand on the Steering Wheel and I have not have Idler pulley braking anymore. Hope this helps!
Don't make any modification, just buy the original Ford Motorcraft Idler pulley and install it. I will say it again, Don't ever start your car with your hand (left hand) holding on the steering wheel, simple as that!