One of the pleasures of owning a car like an Infiniti is a power accessory like a power window; however, a failing Infiniti window regulator can become a severe annoyance. Unfortunately, window regulators are prone to failure because the mechanical parts undergo a tremendous amount of useage, as well as stress from extreme temperatures, dirt and moisture. First, you must determine if the problem comes from the Infiniti window regulator, or the motor. However, sometimes the motor or fuses will blow because window regulator has jammed up. To pinpoint whether the problem lies in the motor or electrical components, listen for any noise when you press the window switch. If there is just silence, it is more likely that the switch, wiring, fuses or motor are the problem. To pinpoint the problem with the electrical door system, visually inspect the fuses and wiring for signs that the system had blown. Consult your Infiniti owner's manual and study the wiring diagram, then use a 12-volt test light to check the circuits. But the problem can be traced to your window regulator's mechanical parts if you hear the sound of whirring or grinding. When your Infiniti window regulator fails, the problem is usually due to problems like a broken cable, poor lubrication or a loosened fastener. Because of the labor and effort that is required to dismantle a door panel to remove a broken window regulator, it is worth your time and money to purchase a new Infiniti window regulator set here, and install it yourself.