Title: Check the heating, ventilation, and air conditioning (HVAC) controls.
Course: Diesel Equipment Technology I (20107-I) > Section: Preventive Maintenance and Inspection: Servicing the Cab and Hood Instruments and Controls

Checking should include

- operating the HVAC temperature controls and noting temperature changes
- operating the outlet controls and noting how airflow from the vent changes
- operating the defroster mode and verifying the air conditioning (A/C) compressor engages.

ASE 1: VI. Heating, Ventilation, and Air Conditioning: D. Operating Systems and Related Controls (P-1)

Process/Skill Questions:

- When the temperature is moved to hot, does hot air come out of the vents?
- When the temperature is moved to cold, does cold air come out of the vents?
- When the outlet controls are operated, does air come out of the vent indicated (e.g., foot/vent/defroster)?
- When the defroster mode is selected, did the A/C compressor engage?