Heater A/C System - Defaults To Defrost Mode
NUMBER: 24-24-99GROUP: Heating & A/C
DATE: Nov. 12, 1999
SUBJECT:
Heater A/C system changes to defrost mode when accelerating
OVERVIEW:
This bulletin involves installing a vacuum check valve in the Heater A/C vacuum supply line.
MODELS:
1999 - 2000 (WJ) Grand Cherokee
NOTE:
THIS BULLETIN APPLIES TO VEHICLES EQUIPPED WITH MANUAL HEATING & A/C SYSTEMS.
SYMPTOM/CONDITION:
The heater A/C system may default to the defrost mode when accelerating. This will most likely happen in heavy throttle situations such as trailer towing or accelerating up steep grades.
DIAGNOSIS:
If customers complain of this condition, perform the Repair Procedure.
PARTS REQUIRED:
1 04677204 Check valve
AR npn Vacuum hose
REPAIR PROCEDURE:
THIS REPAIR IS COMPATIBLE WITH DAIMLERCHRYSLER'S MOBILE SERVICE PROGRAM AND DOES NOT REQUIRE HOISTS OR OTHER FULL SERVICE FACILITY SPECIAL EQUIPMENT.
1. Open the hood and locate the heater A/C system vacuum supply line (See Figure 1).
2. Disconnect the vacuum line from the tee. Determine the direction of flow through the check valve. Install the check valve, p/n 04677204, between the tee and the line, making sure that vacuum will flow in the direction of the vacuum source.
POLICY: Reimbursable within the provisions of the warranty.
TIME ALLOWANCE:
Labor Operation No: 24-50-47-93 0.2 Hrs.
FAILURE CODE: P8 - New Part