Jim.B-
If Fleetwood used the circuit provided by Ford (some manufacturers do, some don't), then the fuse to power that circuit is #22 in the Ford "Battery Junction Box" (BJB). See
this link, page 20, "Cigarette Lighter Feed." It's a 20A fuse.
The BJB is mounted under the hood, on the firewall, in the middle of the coach, up high. I believe your coach's BJB has a series of arrows on the front cover that point toward the release latch. The link above (page 21) shows where to find fuse #22 in the BJB.
Some Fleetwoods may have a fuse for the 12V sockets in the BCC, Battery Control Center.
This post shows a picture of the outside of a BCC.