Pretty much. Unless I'm missing something the temp. sensor/spring/air bleed valve unit opens vacuum flow when air temperature is somewhere under 100F, though the book says it triggers when the temperature is below 85F. The vacuum triggers the diaphragm on the snorkel operating the damper door, so the stove pipe can bake the air cleaner, pretty simple.
recalling an SStim post "you're going around the block to go next door". Still took me this long to understand it really has nothing to do with the choke less allowing it to work for efficiently.
The diaphragm on the snorkel is also called a motor I guess. The manual mentions it just enough to be confusing, a miss on their illustration
. Perhaps I'm missing it. I don't know enough why it's characterized as a motor.
Very cool system if it works. I wonder if anyone can attest to the expected life of sensors and diaphragms? I know my diaphragm is good. The system was disconnected before I got the truck in 1989. Luck has it someone knew enough to delete the vacuum source, I'd think that would toast the diaphragm without a stove pipe. Just for kicks pics of the damper door..