I have a ‘55 2nd Series with a “Deluxe TwinAir” heater. Unit has a defroster lever, a two speed fan that works; but no temperature control I can find except for door on either side of the heater box. Doors can opened or closed. Heater hose from engine to heater unit and return to engine, but no inline control valve on hoses.
Anyone know how this works? Just either open or close the side doors? No intake air from anywhere. Side doors are open in attached photo.
Thanks
Geoff
1955 2nd Series 3600 235 cid, 4 sp. - Current 1979 Chevy K10 350 cid 4 sp -Sold 1955 2nd Series Wide Window 283 cid 3 sp - Totaled