The 2000 Lincoln LS doesn't have a single fuse dedicated solely to the heater controls. The heater controls, blower motor, and other related components are likely protected by several fuses and relays, depending on the specific circuit. These fuses would be related to the climate control system and possibly power distribution.
To find out which fuses might be relevant, you need to consult your owner's manual. It will have a fuse box diagram showing the location of fuses and what circuits they protect. If you don't have the manual, you can usually find a downloadable version online by searching for "[year] Lincoln LS owner's manual" .
