Hello pamthevan and welcome to the forum.
If it’s part of leisure electrics then it might not be OEM and you might need to pull off some interior panels to trace the wiring back. Is there any other circuitry that also does not work? If so, it might share a fuse with that. The 12V in my van is definitely leisure electrics and the wiring diagram for the leisure electrics on mine is on my show us yours page, but I’d expect a SC from 2000 to be very different and a wiring diagram doesn’t help much to figure where stuff is location, obvs.
The long post at the top of my show us yours page has practically everything I know about parts, resources and the like and the info there might be a good place to start to understand aspects of your van.
The post there will also suggest that the best resource for electrics is the manual that’s downloadable from Hiacesoutheast. Fine if it’s OE wiring, but if not get some trim tools a borescope and a volt meter. When possible can you upload a picture of the offending part? I don’t know where the 12V socket is on a 2000 SC. You might need to make a couple more posts before you can upload a picture.
Ta and good luck!