This article will help you identify where your Fusebox location is and how to identify your Starter Relay.
The images below are examples of Kia Optima’s ranging from 2010 – 2023 engine compartments and their respective Fusebox locations. Yours should look similar.
Once you locate your Fusebox, remove the cover and flip it over. You should see a diagram which identifies all your fuses and relays.
You are looking for the box with “START” which should be the Starter Relay.
Your Factory / OEM Starter Relay should look similar to this image.