Why is the electric side mirror not working?

1. The motor needs electrical energy to work, start with the power mirror fuse. Your car owner's manual should tell you where to locate the fuse box, what specific fuse location and the fuse size. When you find this fuse, check if it is blown. Don't know how, bring it to auto parts store and they can probably tell you. If you replace it and fuse blows again, you need to have the power mirror circuit checked by a qualifed service technician. Do not be tempted to replace with a fuse of higher rating because you risk creating more problems on your car. It blows for a reason and that is what it is supposed to do. 2. If the fuse is good, it can be the power window motor, the switch or wiring. At this point it is best to have it checked by a qualified service person. This could be a very involved process that an average car owner might not be able to do without the proper tools and skills diagnosing each component.