to get the switch off you have to unscrew the bezel, which has small notches you can push with a screwdriver to loosen - sounds like it's the red wire to the battery that got fired ... could be anything that caused it
"When we tug a single thing in nature, we find it attached to the rest of the world" ~ John Muir "When we tug a single thing on an old truck, we find it falls off" ~ me Some TF series details & TF heater pics