This is the fan/heater demister unit. This has to be fitted in AUS for you to get the car registered. The 2 speeds on the fan are determined by the heater controls on the dash. The little coil thing inside the unit is the resistor that enables the low fan speed. If you want it to only operate as a fan, just remove the heater core at the base, and eith plug up, or connect up the heater hoses from the engine, with a long piece of heater hose. I think even if you had airconditioning, this unit should still be in the car. Later model boxes look different. This particular one is from the 1970-1973 model 1200s. The later model ones were made by "Smiths" from memory, and had some metal construction, and kind of looked like 1600 (510) units. The heat for heater/demisters is always derived rfom radiator coolant water. The heat of the engine provides the heat for the demister.

The blue wires at the back are the power feed wires to make the thing turn.

Cheers,
Chris