AC Ducts - Emit Odors
NO.: 24-21-93GROUP: Air Conditioning
DATE: Sep. 3, 1993
SUBJECT:
Air Conditioning Ducts Emits Odor
NOTE:
THIS BULLETIN SUPERSEDES TECHNICAL SERVICE BULLETIN 24-12-92. ALL REVISIONS ARE HIGHLIGHTED WITH **ASTERISKS**
MODELS:
1992**- 1993** (AC) Dynasty/New Yorker Salon
(built after Jan. 31, 1992 - MDH 0131XX)
1992**- 1994** (AS) Caravan/Grand Caravan/Caravan CV
Voyager/Grand Voyager/Town & Country
1992**- 1993** (AY) Imperial/New Yorker Fifth Avenue
(built after Jan. 31, 1992 - MDH 0131XX)
SYMPTOM/CONDITION:
Some vehicles may emit an 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 WITH LESS THAN 12,000 MILES
**On some vehicles with the plate fin A/C evaporator, 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.
To correct this condition, the evaporator coil in the A/C unit must be replaced. Refer to the appropriate service manual for the replacement procedure.
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 A/C 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 by the repair procedure outlined in this bulletin.
PARTS AND EQUIPMENT REQUIRED:
VEHICLES WITH LESS THAN 12,000 MILES
1 Coil, A/C Evaporator
AS 1992 4723069
AS 1993 - 1994 4474842
AC & AY 4677011
VEHICLES IN SERVICE FOR 12 MONTHS OR MORE
1 A/C Evaporator Cleaner 4728942
1 Reusable Applicator 4740319
1 Pair Of Rubber Gloves
1 Pair Of Safety Glasses
REPAIR PROCEDURE:
This bulletin involves cleaning and disinfecting the A/C evaporator and housing.
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
1. Verify that the A/C condensation drain tube is free from any blockage and drains freely. Correct if necessary.
2. Protect the interior of the vehicle with a drop cloth.
3. Start the engine, set the blower on HIGH, air on recirculate, 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.
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 vehicles doors. On "AS" Body models, remove the resistor block.
**NOTE:
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 COUNTER-CLOCKWISE SO THE THREADS WILL ENGAGE AND COME OUT.**
5. Shake the bottle of evaporator cleaner. Connect the bottle and a compressed air supply, with at least 80 PSI of pressure, to the reusable applicator.
6. 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.
7. Turn the vehicle OFF and allow to soak for at least 30 minutes.
8. Wipe off any excess cleaner from around the instrument panel ducts.
9. Start the engine, set the blower on HIGH, air on recirculate, **turn the A/C compressor OFF, open all of the instrument panel ducts, and open all of the vehicles windows.** Run the vehicle for 20 minutes to dry the system.
POLICY: Reimbursable within the provisions of the warranty.
TIME ALLOWANCE:
Labor Operation No. Replace Evaporator AC & AY 1992 - 1993
24-65-90-91 2.0 Hrs.
AS 1992 - 1994 24-65-90-91 2.4 Hrs.
Clean Evaporator
AC, AS & AY 24-65-90-90 0.3 Hrs.
FAILURE CODE: 58 - Internal Defect