The dimmer switch doesn't control airflow. There's a dial on the row below that that has "passengers/ driver" which is what can be set to control the flow of air between those.

The Electic booster pump is great on big buses driving on the highway in 0 F weather! The interviewer still did not understand how the system work. Also their are also two master valves under the hood, that must be turn off at about 50 F to prevent the heater box from cooking the driver. There are fan switches for the rear also

Tengo un camión Blue Bird el motor arranca trabaja bien pero el tablero no encienden Y ninguno de los marcadores trabaja de repente se apagaron todos pero el motor sigue trabajando

I use my Heater pump if i stop and park in my bus and want heat for just a few minutes with the engine off.

Thank you so much been wanting to fix the time forever!!

Can you do another bus video