A/C - Unpleasant Musty Odor: Overview

Group: 87

Number: 97-01

Date: Oct. 23, 1997

Subject:
Musty Odor from Heating and Ventilation System

Model(s):
All with A/C All

Condition
Unpleasant "musty" odor from Heating and Ventilation system.

Odor mainly occurs after vehicle has been sitting (unused) at least 5 hours and within 20 to 60 seconds after vehicle is first started.

This odor may be caused by residual condensate in and around evaporator mixing with airborne pollutants. This forms the growth of bacteria and or fungi.

Note:
Condensate is a normal condition in all A/C systems.

This odor can be eliminated by destroying the bacterial and or mold growth using a product called Airsept(R).

Service
Prior to performing Airsept(R) procedure:

^ Condensate drain(s) in bottom of plenum chamber must be open and free of any debris.

^ Bulkhead must be sealed (no leaks/water ingress into passenger compartment) --> Technical Bulletin Group 51 Number 93-02 dated November 15, 1993.

^ Evaporator water drain valve (behind bulkhead insulation) must open freely.