Air Conditioning Ducts - Emits Musty Odor
NO: 24-06-95 Rev. AGROUP: Heater & A/C
DATE: May 26, 1995
SUBJECT:
Air Conditioning Ducts Emit Odor
THIS BULLETIN SUPERSEDES TECHNICAL SERVICE BULLETIN 24-06-95 DATED MAY 5, 1995 WHICH SHOULD BE REMOVED FROM YOUR FILES. THE LABOR OPERATION NUMBERS HAVE BEEN CORRECTED. ALL REVISIONS ARE MARKED WITH **ASTERISKS**.
MODELS:
1994 - 1995 (AB) Ram Van/Wagon (Built On or After Aug. 1, 1993 - MDH 08-01-XX)
1992 - 1993 (AC) Dynasty/New Yorker Salon (Built On or After Jan. 31, 1992 - MDH 01-31 -XX)
1993 - 1995 (AN) Dakota
1992 - 1995 (AS) Caravan/Voyager/Town & Country
1992 - 1993 (AY) Imperial/New Yorker Fifth Avenue (Built On or After Jan. 31, 1992 - MDH 01-31-XX)
1994 - 1995 (BR) Ram Truck
1995 (JA) Cirrus/Stratus
1993 - 1995 (LH) Concord/Intrepid/LHS/New Yorker/Vision
1995 (PL) Neon
1993 - 1995 (ZJ) Grand Cherokee/Grand Wagoneer
SYMPTOM/CONDITION:
Some vehicles may emit a "musty" odor from the air conditioning ducts. The odor is most noticeable when the A/C system is first turned on. Two causes for A/C related odors are possible, and are covered separately below:
CAUSE AND CORRECTION - VEHICLES IN SERVICE LESS THAN 12 MONTHS
On some vehicles with "plate fin" A/C evaporators, the manufacturing process occasionally results in an excessive amount of corrosion protection coating being applied on the evaporator external surfaces. A heavy coating can result in an odor from the evaporator fins, especially when dry fins become wet from condensation.
A new coating has been developed to correct this condition. The evaporator coil in the A/C unit must be replaced. Proceed to Repair Procedure A.
CAUSE AND CORRECTION - VEHICLES IN SERVICE FOR 12 MONTHS OR MORE
Offensive odors from air conditioners can sometimes occur in vehicles that have been in extended use resulting from possible accumulation of "foreign matter" in the AC unit. This condition is more likely to occur in vehicles that have been in extended use in humid climates. To correct this condition, the internal surfaces of the A/C air handling system will have to be cleaned. Proceed to Repair Procedure B.
PARTS AND EQUIPMENT REQUIRED:
REPAIR PROCEDURE A - VEHICLES IN SERVICE LESS THAN 12 MONTHS
AR 4798625 Coil, A/C Evaporator (AB 1994-1995, Vehicles Built On or After Aug. 1,1993)
AR 4677011 Coil, A/C Evaporator (AC/AY 1992-1993, Vehicles Built On or After Jan. 31,1992)
AR 4798624 Coil, A/C Evaporator (AN 1993-1995)
AR 4723069 Coil, A/C Evaporator (AS 1992)
AR 4734292 Coil, A/C Evaporator (AS 1993-1994)
AR 4797131 Coil, A/C Evaporator (AS 1995)
AR 4723518 Coil, A/C Evaporator (BR 1994)
AR 4798705 Coil, A/C Evaporator (BR 1995)
AR 4644790 Coil, A/C Evaporator (JA 1995)
AR 4797129 Coil, A/C Evaporator (LH 1993-1995)
AR 4797130 Coil, A/C Evaporator (PL 1995)
AR 4723518 Coil, A/C Evaporator (ZJ 1993-1994)
AR 4798705 Coil, A/C Evaporator (ZJ 1995)
REPAIR PROCEDURE B - VEHICLES IN SERVICE FOR 12 MONTHS OR MORE
1 4728942 A/C Evaporator Cleaner
1 4740319 Reusable Applicator
1 NPN Pair of Rubber Gloves
1 NPN Pair of Safety Glasses
REPAIR PROCEDURE A:
This repair involves checking the A/C condensation drain tube for proper operation and replacing the A/C evaporator coil.
1. Verify that the A/C condensation drain tube is free from any blockage and drains freely. Repair as necessary.
2. Replace the A/C evaporator coil with the appropriate evaporator coil as called out in the Parts and Equipment Required section. Follow all evaporator removal and replacement instructions listed in the appropriate vehicle Service Manual.
REPAIR PROCEDURE B:
This repair involves checking the A/C condensation drain tube for proper operation and cleaning and disinfecting the A/C evaporator coil and housing.
1. Verify that the A/C condensation drain tube is free from any blockage and drains freely. Repair as necessary.
NOTE:
FOLLOW ALL CAUTIONS AND WARNINGS SUPPLIED WITH THE A/C EVAPORATOR CLEANER:
- WEAR SAFETY GLASSES AND GLOVES
- AVOID BREATHING VAPORS
- USE WATER TO FLUSH EYES IF NECESSARY
2. Protect the interior of the vehicle with a drop cloth.
3. Start the engine, set the blower on HIGH, air on RECIRCULATION, turn the A/C COMPRESSOR OFF, open all of the instrument panel ducts and vehicle windows. Run the vehicle for 60 minutes to dry out the evaporator coil.
NOTE:
FAILURE TO DRY THE EVAPORATOR FOR 60 MINUTES WILL NOT EFFECTIVELY PREPARE THE EVAPORATOR COIL FOR CLEANING AND WILL NOT RESOLVE THE ODOR PROBLEM.
4. Switch to OUTSIDE AIR. With a shop rag, block about 90% of the outside air inlet to increase air velocity (the outside air inlet is located outside the vehicle under the cowl on the right side of the dash panel). Open the vehicle doors. On AS Body models, remove the resistor block.
NOTE:
ON "AS" MODELS, THE THREADS OF THE SCREWS ATTACHING THE RESISTOR BLOCK ARE NOT FULL LENGTH. IT IS NECESSARY TO GENTLY PRY OUT THE RESISTOR BLOCK WHILE TURNING THE SCREWS COUNTERCLOCKWISE SO THE THREADS WILL ENGAGE AND COME OUT.
6. Shake the bottle of evaporator cleaner, P/N 4728942. Connect the bottle and a compressed air supply, with at least 80 PSI of pressure, to the reusable applicator, P/N 4740319.
7. Spray the cleaner into the outside air inlet for 20 seconds or until the bottle is completely empty. Spray into the resistor block opening on "AS" models.
8. Turn the vehicle OFF and allow to soak for at least 30 minutes.
9. Wipe off any excess cleaner from around the instrument panel ducts.
10. Start the engine, set the blower on HIGH, air on RECIRCULATE, turn the AC COMPRESSOR OFF, open all of the instrument panel ducts, and open all of the vehicle windows. Run the vehicle for 20 minutes to dry the system.
NOTE:
FAILURE TO DRY THE EVAPORATOR COIL FOR 20 MINUTES WILL NOT RESOLVE THE ODOR PROBLEM.
POLICY:
Reimbursable within the provisions of the warranty.
TIME ALLOWANCE:
Labor Operation No: 24-65-02-95 Evaporator, Replace
1994 (AB) 2.7 Hrs.
1995 (AB) 1.9 Hrs.
1992-93 (AC/AY) 2.0 Hrs.
1993-95 (AN) 2.2 Hrs.
1992-93 (AS) 2.4 Hrs.
1994-95 (AS) 3.8 Hrs.
1994-95 (BR) 3.3 Hrs.
**1995 (JA) 3.7 Hrs.**
1993 (LH) 4.1 Hrs.
1994-95 (LH) 3.4 Hrs.
1995 (PL) 3.9 Hrs.
1993-95 (ZJ) 3.1 Hrs.
Optional Equipment 24-65-02-60 Console Equipped
1992-93 (AS) 0.2 Hrs.
1993-95 (LH) 0.2 Hrs.
24-65-02-66 50/50 Bench Seat
1993-95 (LH) 0.8 Hrs.
FAILURE CODE: P8 - New Part
**24-65-02-94** Evaporator, Clean and
Disinfect 0.7 Hrs.
FAILURE CODE: YP - Odor