The Stovebolt Site Forums The Shop Area General Truck Talk Heater Delete - also defrost delete?

My uncle thought that his 50 had a defroster, but no heater. Is this likely? When I took apart under the dash, there was a cover sealing the vents shut on the passenger side cowl.

Also, were any of the heater controls hand operated under the dash to change position of the flapper door or are they done by cable?

by definition, defrosting requires heat - no heater, no defroster

Bill

My recirculating heater has a cover for the side vent and a handle to change from floor to defrost. No cables. If Grandpa's handle fell off he would have defrost and no heat if the lever was in the defrost position when it broke. But, as red58 posted, the heater must be there to defrost. Are there some hoses to the firewall? You got heater. No hoses? You got cold air drafts. The fan, heater core are all in a sheet metal thing under the glove box, or they are not. Too big to miss.

Some heaters did not use the intake on the passenger side

chevy.oldcarmanualproject.com/accessories/1951am/

1947-55 trucks

First things/answers first: the heater was an accessory. A heater (any heater) was not standard equipment (this might be hard to believe/understand).

Nonetheless, there were defroster vent openings (uncovered) in the dash below the windshield in all truck cabs.

There was a standard-equipment cover plate over the hole in the the lower right side cowl. This hole was used for outside air for one style of heater. The motor for this type of heater protruded through the upper firewall. There was a standard-equipment round cover plate if this heater was not installed.

Small diameter holes (uncovered) for heater hoses were in different locations on the firewall.

One style GM heater, Recirculating Heater, had controls on the heater (and a motor speed switch mounted under the dash).

Another style heater, Air Flow Heater, had controls on the heater, and controls attached to the dash, and a motor speed switch mounted under the dash.

Here are installation instructions (and photos) of those two styles of GM heaters available in 1951 (the same style heaters were available from GM in 1950).

Non-GM accessory heaters might have been installed by the dealer, or by an auto shop, or by the owner.