Mid 1947 has arrived, and GM introduces a completely new truck cab. It was named “Advanced Design,” as it is still called today.
This was the first time for a GM truck cab to be designed so dry outside air could be pulled inside by an accessory heater fan to be warmed. Every cab was now given eleven louvers on the right front cowl panel. Thus, they were always there when a top of a line GM heater was added. This was also referred to as, “The Cab that Breathes.”
Prior to this, the cold windows would “fog” on the inside when the passenger’s breath touched the cold glass. Thus, this even created a market for a small electric fan assembly clamped on the steering column. It kept a flow of air (also having some humidity) across the driver’s side of the windshield for safer driving on very cold days.
Heating non-humid air in the cab from outside was now great for GM truck owners during a very cold season. This “fresh air heater” was dealer installed. Chevrolet dealers always kept several heaters in their parts department to be ready to install when requested.
Another big plus! These units included two defroster outlets (controlled by the driver) that would even more prevent windshield fogging.
The attached photos show this 1947-52 design. A slight update unit came in 1953- early 1955. This new design allowed for it to shut off incoming colder air for a faster cab warm-up. With a turn of a lever, the newer heater could then become a 1947-52 type.
