Can a car window fuse slowly die because your windows are very slow and wires are all hooked up properly and you already replaced one window motor?

if you have already replaced the motor, i would look into getting a window regulator. take some spray silcone and spray the window tracks. when a fuse blows it blows. all the fuse dose is provide a path for current to flow. when it blows there is a "open" in the circuit and current will no longer be able to flow. sounds like it could also be a bad ground.