The ubiquitous round “in cab” Smiths heater has been used on a myriad of British cars. Jaguar, Morris Minor, Triumph, AC and Land Rover…. to name but a few.

The heater takes a hot water feed (operated by a tap on the cylinder head… as you do) from the engine into the heater matrix. The front face of which carries a fan that pushes cool air through the hot matrix; thus distributes less cool air around the cab, or…. by way of two flaps on the front of the unit, air is  “forced” through the ductwork and onto the  windscreen, where it will no doubt decrease the drivers visibility 😉

The heater motor is operated by a rheostat (potentiometer) switch, allowing control of the fan speed… depending on the drivers need to hold a conversation.

The entire unit was stripped and repainted (including new “ironmongery” and manufactures badge) some months ago (I didn’t take any photos) and having tested the motor is back together again.

Component parts of the Smiths heater system
Face place removed and heater matrix exposed
Heater matrix with original 12Volt motor installed. Fan read to fit.
Fan installed 
Rear end of the heater matrix with motor and input & output hot water pipes. The 3 bolts around the motor are passed through the bulkhead to secure the unit.
3 bolts later…. and the matrix is fixed. I soldered on some longer cables onto the original spurs. These will be trimmed to length once I get on with the wiring.
Faceplate of the heater installed
Flaps open. In this position, the cab is heated… to a fashion. 
Screen vents and new ductwork installed
Smiths heater, ductwork and windscreen vents installed…. all we need is some electricity.