A/C Operational Test
A/C Operational Test1. Close all windows and position footwell fresh air vents at ``OFF.''
2. With engine cold, turn lefthand knob to full heat, start engine, and run at 1000 RPM. If camshaft is in cold position, servo will operate for a few seconds and then shutdown. As water temperature reaches 104°F., system will engage, center outlet will close if not already closed, and fans will operate at speed 2. Turn righthand knob to low and check for drop in fan speed.
3. With engine at normal operating temperature, turn lefthand knob to ``65°F.'' Hold suitable heat source approximately 1 inch below sensor inlet hole located below center parcel shelf, then check that unit goes through following sequence in approximately 20 seconds:
a. Blower speeds drop to low.
b. Temperatures decrease, with temperature at upper vents decreasing more rapidly then temperature at footwell vents.
c. After approximately 10 seconds, center outlet flap will open.
d. Approximately 1 second later, fan speed will shift up to medium 1.
e. After approximately 1 more second, fan speed will shift to medium 2.
f. After approximately 1 more second, fan speed will shift to maximum, fresh air vents will close, and recirculating flaps will open. A rush of air into air boxes can be felt at bottom edge of lower trim panels.
4. Turn righthand knob to ``LO'' and ensure fan speed drops, then return righthand knob to ``AUTO.'' On some vehicles servo action may be too fast to allow audible checking of fan speed changes.
5. Remove heat source from sensor. Depending on ambient temperatures, unit should shift off recirculation and blowers should drop to an intermediate speed.
6. Turn right hand knob to defrost and ensure center outlet flap closes and screen outlets open. Air should now be available only at upper ducts. Ensure fans shift maximum speed and hot air blows from upper ducts. Listen for fan vibration.
7. Ensure air can be cut off from side face level vents by turning wheels beneath outlets.
8. Set righthand knob at ``AUTO'' and lefthand knob at ``75°F'' and wait for unit to settle. Ensure fans are on low speed, then turn righthand knob to ``HI'' and ensure fans shift to maximum speed.