* Underhood Fuse Box: This is typically located on the driver's side fender apron, near the battery. It's usually a fairly large, rectangular box.
* Interior Fuse Panel: This is generally found under the dashboard, on the driver's side. You might need to remove a small panel or access door to get to it. The exact location within the dash can vary slightly.
It's best to consult your owner's manual for the precise location and a fuse diagram. If you don't have the manual, you can often find a downloadable PDF version online by searching for "1981 Cadillac Fleetwood owner's manual." Looking at pictures online related to "1981 Cadillac Fleetwood fuse box" can also be helpful.