The 2013 kia optima fog lights not working causes are failed relay or lights burn out prematurely. being able to see at night is important for driving down the road. your lights need to be working or you may get into a wreck. some issues will show up at some point. a faulty wire could come about. lights may burn out prematurely. corrosion is very nasty to deal with. blown fuse can come about. a failed relay equals a failed light source. these issues need to be dealt with quickly. the light bulbs will stop working eventually. if it becomes dull, you will have to replace them. they aren't that expensive, so they won't hurt your bank account.
The 2013 kia optima fog lights may not work for various reasons such as a damage/burnt out bulb, bad fuse, faulty wiring, or a damaged fog light relay.