AC Control Assembly - Component Availability

REF: HEATING & AIR CONDITIONING

NO.: A0002-96

DATE: MAY 31, 1996

MODEL: GS 300

Title GS 300 A/C CONTROL ASSEMBLY SERVICE PARTS

To allow repairs to the A/C Control Assembly, service parts are now available. The following information on parts and troubleshooting will aid you in addressing complaints with the LCD display, night illumination or switch indicators.





PREVIOUSLY AVAILABLE PARTS:





CURRENTLY AVAILABLE PARTS:

TROUBLESHOOTING:





Use the matrix chart as a guide to repairs. Verify necessary inputs to the A/C Control Assembly from the vehicle prior to disassembly. Use the repair manual, A/C System section, to validate inputs such as B+, ILL+, ground, etc..

NOTE:
If the symptom still exists after the suspect areas have been tested and found not to be faulty, replace the amplifier.

AIR CONDITIONING DISASSEMBLY:

1. Remove the Air Conditioning Control Assembly.

2. Separate Control Panel from case.





a. Remove the 2 screws and release the 4 clips to separate the Control Panel from the case.





b. Release the 3 connectors and separate the Control Panel from the case.





c. Remove the Wire Harness (See Fig. 3.)

REPLACEMENT PROCEDURE FOR NIGHT AND LCD ILLUMINATION BULBS:





Use a flat-b laded screwdriver to remove and replace the bulbs.

INSPECTION PROCEDURE:

1. Bulb Circuit -





a. Perform the following tests on suspect Night or LCD Illumination Bulbs. Check for continuity as shown. Replace the bulb if there is no continuity.





b. With known good bulbs installed, check for continuity between the following illumination circuits:

Replace the Control Panel if there is no continuity.

2. Switch Circuit -





a. Push Switch Continuity Inspection:

^ Check that there is continuity between the terminals while the switch is pressed.





^ If there is no continuity, replace the Control Panel.

b. Dial Switch Continuity inspection:





^ While turning the fan, mode or temp dial switch, check for continuity between the terminals as shown in the table. Rotate each dial switch slowly a full revolution clockwise or counterclockwise as directed.

^ Replace the Control Panel if there is no continuity.








NOTE:
The dial switches are designed to be ON (continuity) between each click stop position and be OFF (no continuity) at each click stop position.

3. Indicator Lamp Circuit -

^ Indicator Lamp Circuit Inspection:





Connect two 1.5v dry cell batteries in series. Using the table, check that each suspect indicator lights up.

NOTE:
Since the indicator lamps are LEDs, do not mix the "+" and "-" terminals of the test batteries or apply power to them for more than 3 seconds at a time.





^ If a suspect LED does not light up when tested, replace the Control Panel.





CONTROL PANEL INNER CIRCUITS








PART NUMBER INFORMATION:





WARRANTY INFORMATION: