To find it:
1. Locate the fuse box: This is usually under the dash, on the driver's side.
2. Look closely around the fuse box: The flasher relay is often a small, square or rectangular component plugged into a socket near the fuses. It might be labeled, or you might need to consult your owner's manual for a diagram. Sometimes it's behind a removable panel near the fuse box.
If you can't find it under the dash, it's possible (though less common) that it might be located in a different location, such as within the underhood fuse box (less likely). Again, your owner's manual is your best resource for precise location.