Control System Testing
- 65° selection drives system to maximum cold.
- 85° selection drives system to maximum heat.
- A mode L.E.D. will flash if mode is malfunctioning. (ETCC system only)
- A temperature L.E.D. will flash if temperature control actuator malfunctions. (ETCC system only)
- A disconnected mode door actuator wire will cause mode L.E.D.'s to flash. (ETCC system only)
- An inoperative mode door which is stopped in a position correct for one mode will not cause L.E.D. to flash until control panel calls for actuator to move to another position. (ETCC system only)
- Blower delay affects only heater and bi-level modes. Switch can be checked by touching 65° on control panel. Blower operation at 65° and no blower at 85° indicates a cold engine or a malfunctioning coolant temperature switch circuit. (ETCC system only)
- Blower delay affects only heater and bi-level modes. Check timer by touching 65° on control panel. No blower operation at 65° and blower when 85° is touched indicates malfunction in blower delay timer circuit. (TCC system only)
- Control must have a constant B+ first and then power from ignition switch to work properly.
- An open sensor string will drive the system to maximum heat except at 65° selection.
- A shorted sensor string circuit will drive the system to maximum cold except at 85° selection.