The heater is operated by three sliding controls attached to the instrument binnacle. Two of the controls mechanically regulate the temperature and air flow distribution. The third control is a switch that operates the two speed heater blower. The heater blower operates with the ignition switch in position ’I’ or ’II’, and is completely independent of the air conditioning system.
Operation
Feed from the battery positive terminal is connected to fusible link 5 (C0632-1) of the engine compartment fuse box on a brown wire. Fusible link 5 (C0570-2) then supplies a feed to the ignition switch (C0028-1) on a brown/white wire.
When the ignition switch is in position ’I’ or ’II’, power flows across the switch (C0099-1) to fuse 13 of the passenger compartment fuse box (C0581-5) on a white/orange wire. Fuse 13 (C0581-6) then supplies a feed to the blower motor (C0056-3) on a purple/green wire. When the blower switch is in the ’Off’ position, the blower motor has no route to earth and does not run.
Moving the blower switch to position ’I’, connects the blower motor (C0056-2) to the blower switch (C0058-2) on a green/yellow wire. Power flows through the motor and the in-line resistor to the switch, which is earthed (C0058-3) on a black wire. The motor will now operate at slow speed.
Moving the blower switch to position ’II’, connects the blower motor (C0056-1) directly to the blower switch (C0058-1) on a green/slate wire. Again, the switch is earthed (C0058-3) on a black wire. The blower motor now operates at high speed.