HVAC SYS. MAY INTERMITTENTLY TURN ON IN DEFOG. OR DEFROST. Buick Park Avenue 1994

SUBJECT: HVAC SYSTEM MAY INTERMITTENTLY TURN ON IN DEFOG OR DEFROST MODE BY DEFAULT (SPLICE WIRE INTO CIRCUIT)

MODELS: 1992-94 BUICK LESABRE AND PARK AVENUE

CONDITION:

SOME OWNERS MAY COMMENT THAT THE HVAC SYSTEM TURNS ON IN "DEFOG" OR "DEFROST" MODE WHEN THE VEHICLE IS FIRST STARTED BUT WAS NOT IN THAT MODE WHEN IT WAS SHUT OFF. FOR EXAMPLE, THE SYSTEM MAY HAVE BEEN IN "NORMAL" MODE WHEN THE VEHICLE WAS TURNED OFF AND THE SYSTEM IS IN "DEFROST" MODE WHEN THE VEHICLE IS TURNED ON. THIS CONDITION IS MORE NOTICEABLE WHEN THE BLOWER FAN IS LEFT IN MEDIUM 1 OR MEDIUM 2 POSITIONS.

CAUSE:

THE HVAC BLOWER FAN IS FEEDING VOLTAGE BACK TO THE HVAC CONTROL DURING POWER DOWN. THE HVAC CONTROL THINKS IT IS A BUTTON PRESS AND CHANGES MODE.

CORRECTION:

NOTE: * = 1992-93 MODELS ** = 1994 MODELS

1. REMOVE BLOWER SPEED RELAY FROM UNDERHOOD FUSE BLOCK.

2. REMOVE TERMINAL *1/**30 AND WIRE (CIRCUIT *50/**41) FROM UNDERHOOD FUSE BLOCK (SEE ATTACHMENT).

3. CUT TERMINAL OFF WIRE AND TAPE BACK HARNESS.

4. STRIP CIRCUIT *1444/**442 IN AN AREA TO ALLOW FOR SPLICING.

5. SPLICE A WIRE INTO CIRCUIT *1444/**442 USING SPLICE CLIP, P/N 1839906, WHICH CAN BE FOUND IN TERMINAL REPAIR KIT (J-38125). FOLLOW THE PROCEDURE FOR "SPLICING COPPER WIRE USING SPLICE CLIPS" IN THE SERVICE MANUAL.

6. ATTACH TERMINAL TO OTHER END OF WIRE AND INSERT INTO UNDERHOOD FUSE BLOCK TERMINAL *1/**30.

7. REINSTALL BLOWER SPEED RELAY IN UNDERHOOD FUSE BLOCK.

PARTS ARE CURRENTLY AVAILABLE FROM GMSPO.

WARRANTY INFORMATION:

FOR VEHICLES REPAIRED UNDER WARRANTY, USE:

LABOR OPERATION NUMBER: N6030 USE PUBLISHED LABOR OPERATION TIME.

FIGURES: 1

Object Number: 87019 Size: FS

GENERAL MOTORS BULLETINS ARE INTENDED FOR USE BY PROFESSIONAL TECHNICIANS, NOT A "DO-IT-YOURSELFER". THEY ARE WRITTEN TO INFORM THOSE TECHNICIANS OF CONDITIONS THAT MAY OCCUR ON SOME VEHICLES, OR TO PROVIDE INFORMATION THAT COULD ASSIST IN THE PROPER SERVICE OF A VEHICLE. PROPERLY TRAINED TECHNICIANS HAVE THE EQUIPMENT, TOOLS, SAFETY INSTRUCTIONS AND KNOW-HOW TO DO A JOB PROPERLY AND SAFELY. IF A CONDITION IS DESCRIBED, DO NOT ASSUME THAT THE BULLETIN APPLIES TO YOUR VEHICLE, OR THAT YOUR VEHICLE WILL HAVE THAT CONDITION. SEE A GENERAL MOTORS DEALER SERVICING YOUR BRAND OF GENERAL MOTORS VEHICLE FOR INFORMATION ON WHETHER YOUR VEHICLE MAY BENEFIT FROM THE INFORMATION.