This is the heater shown in the 46-48 sales literature:
This is the fresh air heater that became available at the end of '47 and is in my car:
And these are pictures of that heater in my car:
The inlet of the air duct that takes air from in front of the radiator:
That then goes along under the hood:
Meeting the fan on the firewall when the hood is closed. The cable going up over the duct controls the damper in the duct (bottom of pivot shaft seen near fan port) to control the air going through the duct.
Into the heater coil on the passenger side of the firewall.
To go out both sides of the bottom plus a slit along the bottom unless that damper is pulled up to divert it to the windshield.
Three dashboard controls. Left for defrost. Middle one direction two speed fan switch. Right controls the damper in the hood duct to control the outside air coming in.
