A/C - Whistling Noise With Blower ON

NUMBER: 24-003-08

GROUP: Heating & Air Conditioning

DATE: February 5, 2008

SUBJECT:
Whistle/humming sound from HVAC With Blower On

OVERVIEW:
This bulletin involves repositioning of the heater core seal on the HVAC unit and if necessary applying foil tape to the seal joints.

MODELS:

2007 - 2008 (WK) Grand Cherokee

2007 - 2008 (WH) Grand Cherokee (International Markets)

2007 - 2008 (XK) Commander

2007 - 2008 (XH) Commander (International Markets)

NOTE:
This bulletin applies to vehicles built between June 1, 2007 (O701XXMDH) and November 1, 2007. (1101XXMDH).

SYMPTOM/CONDITION:

Vehicle operator may complain describe that when the HVAC system is on a whistle / humming sound is heard. The sound is usually observed during 3/4 & full blower motor setting but the sound may be able to be heard on any setting. Condition can only be heard after engine is at operating temperature.

DIAGNOSIS:
Start engine and allow vehicle to reach normal operating temperature. Set the blower motor to 3/4 setting and set the temperature to the full hot position. Listen for a whistle or humming sound from the I/P area. If no sound is heard adjust the blower speed to High and listen for a whistle or humming sound from the I/P area. If the whistle or humming sound is heard proceed with the Repair Procedure.





PARTS REQUIRED:

REPAIR PROCEDURE:

1. Gain access to the heater core (8) by removing the passenger lower knee panel.

2. Remove glove box.





3. Remove blend door actuator (Fig. 1).

4. Inspect the seal between the heater core and the HVAC unit. Is the foam seal visable?

a. Yes >>> Proceed to

b. No >>> This bulletin does not apply. Further Diagnosis is required.

5. Using a flat head screw driver push the seal back into place.

6. Cut and apply foil tape over the seam.

POLICY:
Reimbursable within the provisions of the warranty.





TIME ALLOWANCE:





FAILURE CODE:

Disclaimer:
This bulletin is supplied as technical information only and is not an authorization for repair.