for that lower scopp, pretty much - the function of that is to take in fresh air from the cowl vent on that side, which helps if you want the defroster going full blast but it's not so cold you want a lot of heat, or if you just want it open a bit for continuous fresh air

Bill

Moved over to the Passing Lane

"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