I have an 03 grand caravan sport 3.3 when I put the AC on I get a hissing sound from the dash. Any idea what that noise is vac? and how I fix it? Thanks!

 

Welcome to DF
Here is a TSB that may help?
SUBJECT:
Evaporator Hiss Sound
OVERVIEW:
This bulletin involves installing an evaporator inlet flow straightener and a rubber
evaporator insert between the evaporator tubes if necessary.
MODELS:
2002 - 2003 (RS) Town & Country/Caravan/Voyager
NOTE: THIS BULLETIN APPLIES TO VEHICLES EQUIPPED WITH MANUAL
SINGLE ZONE HVAC (SALES CODE HAA) BUILT MARCH 25, 2002 (MDH 0325XX)
THROUGH AND INCLUDING FEBRUARY 26, 2003 (MDH 0226XX) OR MANUAL
DUAL ZONE HVAC (SALES CODE HAD) BUILT JULY 22, 2002 (MDH 0722XX)
THROUGH AND INCLUDING FEBRUARY 26, 2003 (MDH 0226XX).
SYMPTOM/CONDITION:
Some customers may experience a "hiss" sound, that originates from the Heating,
Ventilation, Air Conditioning (HVAC) unit. This may be most noticeable when
operating between 18 C - 27 C (65 F - 80 F).
DIAGNOSIS:
Operate the vehicle in a moderate ambient temperature, 18 C - 27 C (65 F - 80 F).
Run the HVAC system in recirculation, panel mode, A/C off, full heat, high blower for
1 to 2 minutes to heat the evaporator. Switch the HVAC system to outside air, panel
mode, A/C on, full cool, low blower, and maintain a steady engine speed of approximately
2000 rpm. Listen for a "hiss" that will occur when the A/C clutch cycles on.
NOTE: PERFORM THIS PROCEDURE AFTER EACH REPAIR TO THE HVAC
SYSTEM, TO VERIFY THE “HISS” IS NO LONGER PRESENT.
PARTS REQUIRED:
Qty. Part No. Description
AR (1) 04885713AA Flow Straightener, Evaporator Inlet
AR (1) 05061454AA Rubber Evaporator Insert

 

Do I have to remove the dash to access the HVAC so parts can be replaced?

 

I believe it does.