An electric car window motor works the windows and make them go up or down. Depending on the model of the car and if the window motor is new or used, it should last at least four or five years. In many cases, it will last up to around 7 to 8 years. Sometimes if one breaks, you can replace a part of it and it will save you money, but other times this is not possible. Be aware that if your window motor does need to be replaced, and you buy a used one, you should ask how old that used motor is so you won’t be cheated into buying one on its last legs.