A/C - Erratic HVAC Operation & Self Diagnostic Blinks

Group Ref.: HVAC

Bulletin No.: 361102

Date: February, 1994

SUBJECT:
BLOWN FUSE, ERRATIC HVAC OPERATION, AND SELF DIAGNOSTIC FEATURE BLINKS (INSULATE WIRES)

MODELS:
1994 AND PRIOR CHEVROLET AND GMC C/K TRUCKS

CONDITION:

Some owners may experience a blown fuse, erratic HVAC operation, or a blinking HVAC control head self diagnostic indicator.

CAUSE:

Two possible hard to find causes have been discovered for the above symptoms:





- Six way I/P to HVAC connector terminals may short to the ashtray. The connector has slots to accommodate the terminal positive attachment locks that allow metal to metal contact between the exposed terminals and the ashtray (Figure 1).





- The HVAC Harness from the control head to the blower and mode door motors, running across the vehicle just under the dash panel, may chafe against the cassette deck support bracket (Figure 2).

CORRECTION:

Both conditions can be corrected by taping or otherwise shielding the wires from contact with the respective metal edges. If the second condition has caused significant wire damage, repair according to guidelines found in the wire repair section of the appropriate service manual.

WARRANTY INFORMATION:

For vehicles repaired under warranty, use:

Labor Op Description Labor Time

N6030 Wiring and/or Use Published
connector repair, A/C Labor Operation Time